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                                                                   EXHIBIT 10(M)

          AMENDMENTS 1, 2, 3 AND 4 BETWEEN REGISTRANT AND OLD KENT BANK


                        FIRST AMENDMENT TO LOAN DOCUMENTS


         This First Amendment to Loan Documents is made on the 31st day of
December, 1997 (but effective as of the Effective Date set forth below), between
OLD KENT BANK, a Michigan banking corporation (the "Bank"), One Vandenberg
Center, Grand Rapids, Michigan 49503, and RIVIERA TOOL COMPANY, a Michigan
corporation ("Borrower"), 5460 Executive Parkway, Grand Rapids, Michigan 49512.


                                    RECITALS:

         A.   The Bank and the Borrower are parties to a Loan Agreement dated 
June 12, 1997 (the "Loan Agreement"), pursuant to which the Bank has agreed,
subject to the terms and conditions set forth in the Loan Agreement and the Loan
Documents, to extend to the Borrower the following loans: (i) a Revolving L/C
Loan in the maximum principal amount of $10,000,000; (ii) an Existing Equipment
Term Loan in the maximum principal amount of $3,250,000; and (iii) a
Non-Revolving Equipment L/C Loan in the maximum principal amount of $4,000,000.
Capitalized terms used but not defined in this First Amendment shall have the
meanings given such terms in the Loan Agreement.

         B.   The Revolving L/C Loan is evidenced by a Promissory Note in
substantially the form attached to the Loan Agreement as Exhibit A (the
"Revolving L/C Loan Note"), the Existing Equipment Term Loan is evidenced by a
Promissory Note in substantially the form attached to the Loan Agreement as
Exhibit B (the "Existing Equipment Term Loan Note"), and the Non-Revolving
Equipment L/C Loan is evidenced by a Promissory Note in substantially the form
attached to the Loan Agreement as Exhibit C (the "Non-Revolving Equipment L/C
Loan Note").

         C.   The Bank and the Borrower wish to amend the Loan Agreement and the
Notes in the manner set forth below.

         NOW, THEREFORE, the Bank and the Borrower agree as follows:

         1.       Change in Interest Rates.  Effective as of September 1, 1997 
(the "Effective Date"):

                  (a) The Revolving L/C Loan shall bear interest at the Prime
         Rate.

                  (b) The Existing Equipment Term Loan shall bear interest at
         the Prime Rate, unless and until the Borrower duly exercises its option
         under the applicable Loan Documents to change the interest rate on the
         Existing Equipment Term Loan to the rate of interest that is equal to
         the Five (5)-Year Treasury Rate on the Interest Rate Determination Date
         plus 275 basis points.



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                  (c) The Non-Revolving Equipment L/C Loan shall bear interest
         at the Prime Rate, unless and until the Borrower duly exercises its
         option under the applicable Loan Documents to change the interest rate
         on the Existing Equipment Term Loan to the rate of interest that is
         equal to the Six (6)-Year Treasury Rate on the Interest Rate
         Determination Date plus 275 basis points.

         2.   Effect of this First Amendment. The Loan Agreement, the Notes, and
the other Loan Documents are hereby amended as required (and only as required)
to give effect to the change in the interest rates for the Loans expressly
provided for in paragraph 1 of this First Amendment. Each and every one of the
Loan Documents shall be deemed to have been amended by this First Amendment as
if such Loan Documents had been specifically amended by separate instrument.
This First Amendment shall be a Loan Document, and all references in any Loan
Document to the "Loan Documents" shall refer to the Loan Documents as amended by
this First Amendment.

         3.   No other Amendments, etc. Except as expressly set forth above, the
Loan Agreement, each of the Notes, and all of the other Loan Documents shall
remain in full force and effect as originally executed and delivered by the
parties, and are hereby ratified and affirmed by the undersigned.


         IN WITNESS WHEREOF, the parties have executed this Agreement as of the
day and year first above written.


WITNESSES:


/s/ Gilbert A Segovia                     RIVIERA TOOL COMPANY
---------------------------

/s/ Peter C. Canepa                       By: /s/ Kenneth K. Rieth   
---------------------------                   -----------------------------
                                              Kenneth R. Rieth, President




/s/ Peter C. Canepa                       OLD KENT BANK
---------------------------

/s/ Kenneth K. Rieth                      By: /s/ Gilbert A Segovia  
---------------------------                   -----------------------
                                              Gilbert A. Segovia, Vice President



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                       SECOND AMENDMENT TO LOAN DOCUMENTS


         This Second Amendment to Loan Documents is made on the 15th day of
February, 1998, between OLD KENT BANK, a Michigan banking corporation (the
"Bank"), One Vandenberg Center, Grand Rapids, Michigan 49503, and RIVIERA TOOL
COMPANY, a Michigan corporation ("Borrower"), 5460 Executive Parkway, Grand
Rapids, Michigan 49512.


                                    RECITALS:

         A.   The Bank and the Borrower are parties to a Loan Agreement dated 
June 12, 1997 (the "Loan Agreement"), as amended by a First Amendment to Loan
Documents dated as of December 31, 1997 (the "First Amendment"), pursuant to
which the Bank has agreed, subject to the terms and conditions set forth in the
Loan Agreement and the Loan Documents, as so amended, to extend to the Borrower
certain credit facilities, including but not limited to a Revolving L/C Loan in
the maximum principal amount of $10,000,000.00. Capitalized terms used but not
defined in this Second Amendment shall have the meanings given such terms in the
Loan Agreement, as amended.

         B.   The Revolving L/C Loan is evidenced by a Promissory Note in
substantially the form attached to the Loan Agreement as Exhibit A (the
"Revolving L/C Loan Note").

         C.   The Bank and the Borrower wish to amend the Loan Agreement and the
Revolving L/C Note in the manner set forth below.

         NOW, THEREFORE, the Bank and the Borrower agree as follows:

         1.   Change in Maturity Date of Revolving L/C Loan. Effective as of the
date of this Second Amendment, the maturity date of the Revolving L/C Loan shall
be extended from January 1, 1999 to March 1, 1999.

         2.   Effect of this Second Amendment. The Loan Agreement, the Revolving
L/C Note, and the other Loan Documents are hereby amended as required (and only
as required) to give effect to the extension of the maturity date of the
Revolving L/C Loan expressly provided for in paragraph 1 of this Second
Amendment. Each and every one of the Loan Documents shall be deemed to have been
amended by this Second Amendment as if such Loan Documents had been specifically
amended by separate instrument. This Second Amendment shall be a Loan Document,
and all references in any Loan Document to the "Loan Documents" shall refer to
the Loan Documents, as amended by the First Amendment and as further amended by
this Second Amendment.

         3.   No other Amendments, etc. Except as expressly set forth above, the
Loan Agreement, each of the Notes, and all of the other Loan Documents shall
remain in full force and effect as originally executed and delivered by the
parties, and as previously amended by the First Amendment, and are hereby
ratified and affirmed by the undersigned.


                [REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]


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         IN WITNESS WHEREOF, the parties have executed this Agreement as of the
day and year first above written.


WITNESSES:


/s/ Gilbert A Segovia                     RIVIERA TOOL COMPANY
---------------------------


/s/ Peter C. Canepa                       By: /s/ Kenneth K. Rieth
---------------------------                   ----------------------------------
                                              Kenneth R. Rieth, President




/s/ Peter C. Canepa                       OLD KENT BANK
---------------------------

 /s/ Kenneth K. Rieth                     By: /s/ Gilbert A Segovia  
---------------------------                   ----------------------------------
                                              Gilbert A. Segovia, Vice President


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                        THIRD AMENDMENT TO LOAN DOCUMENTS


         This Third Amendment to Loan Documents is made on the 14th day of
August, 1998, between OLD KENT BANK, a Michigan banking corporation (the
"Bank"), One Vandenberg Center, Grand Rapids, Michigan 49503, and RIVIERA TOOL
COMPANY, a Michigan corporation ("Borrower"), 5460 Executive Parkway, Grand
Rapids, Michigan 49512.


                                    RECITALS:

         A.   The Bank and the Borrower are parties to a Loan Agreement dated 
June 12, 1997 (the "Loan Agreement"), as amended by a First Amendment to Loan
Documents dated December 31, 1997 (the "First Amendment") and a Second Amendment
to Loan Documents dated February 15, 1998 (the "Second Amendment"), pursuant to
which the Bank has agreed, subject to the terms and conditions set forth in the
Loan Agreement and the Loan Documents, as so amended, to extend to the Borrower
the following loans: (i) a Revolving L/C Loan in the maximum principal amount of
$10,000,000; (ii) an Existing Equipment Term Loan in the maximum principal
amount of $3,250,000; and (iii) a Non-Revolving Equipment L/C Loan in the
maximum principal amount of $4,000,000. Capitalized terms used but not defined
in this Third Amendment shall have the meanings given such terms in the Loan
Agreement, as previously amended.

         B.   The Revolving L/C Loan is evidenced by a Promissory Note in
substantially the form attached to the Loan Agreement as Exhibit A (the
"Revolving L/C Loan Note"), the Existing Equipment Term Loan is evidenced by a
Promissory Note in substantially the form attached to the Loan Agreement as
Exhibit B (the "Existing Equipment Term Loan Note"), and the Non-Revolving
Equipment L/C Loan is evidenced by a Promissory Note in substantially the form
attached to the Loan Agreement as Exhibit C (the "Non-Revolving Equipment L/C
Loan Note").

         C.   The Bank and the Borrower wish to amend the Loan Agreement and the
Notes in the manner set forth below.

         NOW, THEREFORE, the Bank and the Borrower agree as follows:

         1.       Change in Interest Rates.  Effective as of June 1, 1998 (the 
"Effective  Date"),  the Borrower may elect,  subject to the terms of this 
Agreement, to have:

                  (a)      The unpaid principal balance of the Revolving L/C
                           Loan indebtedness bear interest at a rate that is
                           equal to: (i) the Prime Rate minus 25 basis points
                           (such interest rate is referred to below as the
                           "Prime-Based Index"); or (ii) 225 basis points plus
                           the LIBOR (London Inter-bank Offered Rate) for the
                           applicable LIBOR Period described in paragraph (d)
                           below (such interest rate is referred to below as the
                           "LIBOR-Based Index"). In the absence of an effective
                           election by the Borrower to have the interest rate on
                           all or part of the Revolving L/C Loan determined on
                           the basis of the LIBOR Index, interest on such
                           indebtedness shall be determined on the basis of the
                           Prime-Based Index.

                  (b)      The unpaid principal balance of the Existing
                           Equipment Term Loan bear interest at a rate that is
                           equal to: (i) the Prime-Based Index; or (ii) the
                           LIBOR-Based Index; or (iii) 250 basis points plus the
                           Five (5)-Year Treasury Rate on the Interest Rate
                           Determination Date, as provided in Section 4.1(b) of
                           the Loan Agreement (such interest rate is referred to
                           below as the "5-Year Treasury-Based Index"). In the
                           absence of an effective election by the Borrower to
                           have the interest rate on all or part of the Existing
                           Equipment Term Loan determined on the basis of the
                           LIBOR-Based Index or the 5-Year Treasury-Based 



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                           Index, interest on such indebtedness shall be
                           determined on the basis of the Prime-Based Index.

                  (c)      The unpaid principal balance of the Non-Revolving
                           Equipment L/C Loan bear interest at a rate that is
                           equal to: (i) the Prime Rate Index; or (ii) the
                           LIBOR-Based Index; or (iii) 250 basis points plus the
                           Six (6)-Year Treasury Rate on the Interest Rate
                           Determination Date, as provided in Section 4.1(c) of
                           the Loan Agreement (such interest rate is referred to
                           below as the "6-Year Treasury-Based Index"). In the
                           absence of an effective election by the Borrower to
                           have the interest rate on all or part of the
                           Non-Revolving Equipment L/C Loan determined on the
                           basis of the LIBOR-Based Index or the 6-Year
                           Treasury-Based Index, interest on such indebtedness
                           shall be determined on the basis of the Prime-Based
                           Index.

                  (d)      The applicable LIBOR Period for any indebtedness
                           under the Loan Agreement for which interest is
                           determined on the basis of the LIBOR-Based Index
                           shall be one of the following, as specified in
                           writing by the Borrower when giving notice to the
                           Bank pursuant to paragraph (g) below: (i) loans
                           having 30-day maturities, (ii) loans having 60-day
                           maturities, and (iii) loans having 90-day maturities;
                           provided, however, that the Borrower may not select a
                           LIBOR Period that extends beyond the maturity date
                           for the pertinent Loan.

                  (e)      For any Loan as to which the Borrower elects the
                           LIBOR-Based Index, the original principal amount with
                           respect to which interest may be determined on the
                           basis of the LIBOR-Based Index shall be not less than
                           $500,000, or whole multiples of that amount, as
                           specified in writing by the Borrower when giving
                           notice to the Bank pursuant to paragraph (g) below.

                  (f)      Subject to compliance with paragraph (e) above, the
                           Borrower may elect to divide the unpaid principal
                           balance of a Loan into two or more segments (each
                           such segment is referred to as a "Loan Segment"), and
                           to have interest as to one Loan Segment determined on
                           the basis of the Prime-Based Index and interest as to
                           the other Loan Segment(s) determined on the basis of
                           the LIBOR-Based Index; different LIBOR Periods may be
                           used for each Loan Segment as to which the
                           LIBOR-Based Index has been designated.

                  (g)      If the Borrower elects to have interest for the
                           Existing Equipment Term Loan determined on the basis
                           of the 5-Year Treasury-Based Index, such election
                           must be made as to the entire principal balance of
                           such Loan; likewise, if the Borrower elects to have
                           interest for the Non-Revolving Equipment L/C Loan
                           determined on the basis of the 6-Year Treasury-Based
                           Index, such election must be made as to the entire
                           principal balance of such Loan.

                  (h)      To make an election to have the interest on the
                           Borrower's indebtedness to the Bank determined on the
                           basis of the LIBOR-Based Index, the Borrower shall
                           give the Bank written notice on the Bank's standard
                           request form, which is attached hereto as Exhibit A.
                           Any such election shall become effective upon the
                           later of: (i) the third (3rd) Business Day after the
                           Bank's receipt of such written notice or (ii) the
                           funding date specified in such written notice.

                  (i)      The Borrower may prepay, in whole or in part, a Loan
                           or Loan Segment with respect to which interest in
                           determined on the basis of the LIBOR-Based Index;
                           provided, however that simultaneously with making any
                           such prepayment, the Borrower shall pay, in addition
                           to the accrued interest on the amount prepaid through
                           the date of prepayment, an 


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<PAGE>   7

                           amount equal to the interest that would have accrued
                           through the applicable LIBOR Period on the principal
                           amount so prepaid.

                  (j)      During the continuation of an Event of Default under
                           the Loan Agreement, the Borrower shall have no right
                           to change the rate at which interest is payable on
                           the outstanding indebtedness under any of the Loans.

         2.       Change in Maturity Date of Revolving L/C Loan. As of the 
Effective Date, the maturity date of the Revolving L/C Loan shall be extended 
from March 1, 1999 to January 1, 2000.

         3.       Changes in Certain Financial  Covenants.  As of the Effective 
Date,  Sections 6.8, 6.9 and 6.10 of the Loan Agreement shall provide as 
follows:

                  6.8      Maintain Tangible Net Worth (the applicable amount
                           for each date of determination being referred to
                           herein as the "Minimum Net Worth") of:
                           (a)      not less than  $11,500,000  for the period  
                                    beginning  on August 31,  1997 and ending on
                                    August 30, 1998;

                           (b)      not less than  $14,000,000  for the period  
                                    beginning  on August 31,  1998 and ending on
                                    August 30, 1999; and

                           (c)      For the period beginning on August 31, 1999
                                    and ending on August 30, 2000, and for each
                                    like period thereafter until all of the
                                    Borrower's indebtedness to the Bank has been
                                    repaid in full, with interest, the
                                    Borrower's Minimum Net Worth requirement
                                    shall be increased by $500,000 over the
                                    Borrower's Minimum Net Worth requirement in
                                    effect for the immediately preceding period.

                  6.9      Maintain Working Capital of not less than $9,000,000.

                  6.10     Maintain a ratio of total Liabilities to Tangible Net
                           Worth of not more than 1.2:1.

         4.       Effect of this Third Amendment. The Loan Documents are hereby
amended as required (and only as required) to give effect to the amendments
expressly provided for in this Third Amendment. Each and every one of the Loan
Documents shall be deemed to have been amended by this Third Amendment as if
such Loan Documents had been specifically amended by separate instrument. This
Third Amendment shall be a Loan Document, and all references in any Loan
Document to the "Loan Documents" shall refer to the Loan Documents, as
previously amended by the First and Second Amendments to Loan Documents, and as
further amended by this Third Amendment.

         5.       No other Amendments, etc. Except as expressly set forth above,
the Loan Agreement, each of the Notes, and all of the other Loan Documents shall
remain in full force and effect as originally executed and delivered by the
parties, as previously amended by the First and Second Amendments to Loan
Documents, and as further amended by this Third Amendment, and are hereby
ratified and affirmed by the undersigned.


                [REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]


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<PAGE>   8

         IN WITNESS WHEREOF, the parties have executed this Third Amendment to
Loan Documents as of the day and year first above written.


WITNESSES:


/s/ Gilbert A Segovia                     RIVIERA TOOL COMPANY
---------------------------

/s/ Peter C. Canepa                       By: /s/ Kenneth K. Rieth     
---------------------------                   ----------------------------------
                                              Kenneth R. Rieth, President




/s/ Peter C. Canepa                       OLD KENT BANK
---------------------------

_/s/ Kenneth K. Rieth                     By: /s/ Gilbert A Segovia  
---------------------------                   ----------------------------------
                                              Gilbert A. Segovia, Vice President


                                       4
<PAGE>   9
                       FOURTH AMENDMENT TO LOAN DOCUMENTS


         This Fourth Amendment to Loan Documents is made on the 14th day of
August, 1998, by and between OLD KENT BANK, a Michigan banking corporation (the
"Bank"), One Vandenberg Center, Grand Rapids, Michigan 49503, and RIVIERA TOOL
COMPANY, a Michigan corporation ("Borrower"), 5460 Executive Parkway, Grand
Rapids, Michigan 49512.


                                    RECITALS:

         A.   The Bank and the Borrower are parties to a Loan Agreement dated
June 12, 1997 (the "Loan Agreement"), as amended by a First Amendment to Loan
Documents dated December 31, 1997 (the "First Amendment"), a Second Amendment to
Loan Documents dated February 15, 1998 (the "Second Amendment"), and a Third
Amendment to Loan Documents dated the date of this Fourth Amendment (the "Third
Amendment"), pursuant to which the Bank has agreed, subject to the terms and
conditions set forth in the Loan Agreement and the Loan Documents, as so
amended, to extend to the Borrower certain credit facilities, including but not
limited to a Revolving L/C Loan in the maximum principal amount of $10,000,000.
Capitalized terms used but not defined in this Fourth Amendment shall have the
meanings given such terms in the Loan Agreement, as previously amended.

         B.   The Revolving L/C Loan is evidenced by a Promissory Note in
substantially the form attached to the Loan Agreement as Exhibit A (the
"Revolving L/C Loan Note").

         C.   The Bank and the Borrower wish to amend the Loan Agreement and the
Revolving L/C Loan Note in the manner set forth below.

         NOW, THEREFORE, the Bank and the Borrower agree as follows:

         1.   Temporary Change in Availability Formula. Effective as of August
1, 1998, the following provision shall be substituted for the corresponding
provision appearing in Section 3.1(a) of the Loan Agreement (page 9 of the Loan
Agreement):

                   Availability:             At no time shall the outstanding
                                             balance of the Revolving L/C Loan
                                             exceed the lesser of (1) the Loan
                                             Maximum, or (2) the sum of (a) 85%
                                             of Eligible Accounts Receivable
                                             plus (b) the lesser of (i)
                                             $5,000,000, or (ii) 40% of the Work
                                             in Process Inventory.

         2.   Reversion to Original Availability Formula. Effective as of 
November 1, 1998, the following provision shall, without further act by the Bank
or the Borrower, be substituted for the availability formula set forth in
paragraph 1 above, and the availability formula set forth in paragraph 1 above
thereupon shall cease to be effective:

                   Availability:             At no time shall the outstanding
                                             balance of the Revolving L/C Loan
                                             exceed the lesser of (1) the Loan
                                             Maximum, or (2) the sum of (a) 85%
                                             of Eligible Accounts Receivable
                                             plus (b) the lesser of (i)
                                             $3,500,000, or (ii) 40% of the Work
                                             in Process Inventory.

         3.   Effect of this Fourth Amendment. The Loan Documents are hereby
amended as required (and only as required) to give effect to the amendments
expressly provided for in this Fourth Amendment. Each and every one of the Loan
Documents shall be deemed to have been amended by this Fourth Amendment as if
such Loan Documents had been specifically amended by separate instrument. This
Fourth Amendment shall be a Loan Document, and all references in any Loan
Document to the "Loan Documents" shall refer to the Loan Documents, as
previously amended by the First, Second and Third Amendments to Loan Documents,
and as further amended by this Fourth Amendment.

         4.   No other Amendments, etc. Except as expressly set forth above, the
Loan Agreement, each of the Notes, and all of the other Loan Documents shall
remain in full force and effect as originally executed and delivered by the
parties, as previously amended by the First, Second and Third Amendments to Loan
Documents, and as further amended by this Fourth Amendment, and are hereby
ratified and affirmed by the undersigned.



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         IN WITNESS WHEREOF, the parties have executed this Fourth Amendment to
Loan Documents as of the day and year first above written.


WITNESSES:


/s/ Gilbert A Segovia                     RIVIERA TOOL COMPANY
---------------------------

/s/ Peter C. Canepa                       By: /s/ Kenneth K. Rieth     
---------------------------                   ----------------------------------
                                              Kenneth R. Rieth, President




/s/ Peter C. Canepa                       OLD KENT BANK
---------------------------

/s/ Kenneth K. Rieth                      By: /s/ Gilbert A Segovia  
---------------------------                   ----------------------------------
                                              Gilbert A. Segovia, Vice President


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