<PAGE>
                                                                  EXHIBIT 10(bb)

                       SEVENTH AMENDMENT TO LOAN DOCUMENTS


         This Seventh Amendment to Loan Documents (this SEVENTH AMENDMENT) is
dated as of December 15, 2002, by and between FIFTH THIRD BANK, a Michigan
banking corporation f/k/a Old Kent Bank (the BANK), One Vandenberg Center, Grand
Rapids, Michigan 49503, and RIVIERA TOOL COMPANY, a Michigan corporation (the
BORROWER), 5460 Executive Parkway, Grand Rapids, Michigan 49512.


                              BACKGROUND STATEMENT:

         A. The Bank and the Borrower are parties to a First Restated Loan
Agreement dated as of August 31, 1999, as amended by the First, Second, Third,
Fourth, Fifth and Sixth Amendments thereto (the First Restated Loan Agreement,
as so amended, and all future amendments, renewals and replacements thereof, is
referred to below as the LOAN AGREEMENT). Capitalized terms used but not defined
in this Seventh Amendment shall have the meanings given them in the Loan
Agreement.

         B. The Bank agreed, subject to the terms and conditions set forth in
the Loan Agreement and the other Loan Documents, to extend to the Borrower
certain credit facilities. The Borrower's indebtedness to the Bank is evidenced
by certain Promissory Notes more particularly described in the Fifth Amendment
to Loan Agreement (all such Promissory Notes are referred to collectively below
as the PROMISSORY NOTES.) All of the Borrower's indebtedness to the Bank,
whether for principal, interest or otherwise, is due and payable December 15,
2002.

         C. The Borrower has notified the Bank that the Borrower will not be
able to pay its indebtedness to the Bank on December 15, 2002, and the Borrower
has requested that the Bank extend the maturity date of the Promissory Notes to
January 13, 2003. The Bank has agreed to do so, on the terms and conditions set
forth below, all of which are acceptable to the Borrower.

         The Bank and the Borrower agree that:

         1. Maturity Date of Indebtedness. All of the Borrower's indebtedness to
the Bank, including but not necessarily limited to that evidenced by: (a) the
Revolving L/C Loan Note; (b) the $3,250,000 Existing Equipment Term Loan Note;
(c) the $4,000,000 Equipment Term Loan Note; (d) the 1999 Equipment L/C Note in
the stated principal amount of $3,271,000; (e) the $1,000,000.00 Term Loan Note;
and (f) the Overline Note, shall be due and payable in full on January 13, 2003,
unless sooner accelerated or paid. Until then, the Borrower shall continue to
make payments due the Bank on all such other indebtedness in accordance with the
respective Notes that evidence such indebtedness.

         2. Application of Payments. So long as there exists no Event of Default
(other than an existing Event of Default disclosed in EXHIBIT B to the Fourth
Amendment) under the Loan


                                       1
<PAGE>

Agreement or any of the other Loan Documents, nor any fact, circumstance or
condition which, with notice, or the passage of time, or both, might constitute
an Event of Default (other than an existing Event of Default disclosed in
EXHIBIT B to the Fourth Amendment) under the Loan Agreement or any of the other
Loan Documents, all payments made by the Borrower to the Bank during the period
beginning on the date of this Seventh Amendment and ending January 13, 2003,
shall be applied first to payment of accrued and unpaid interest due under the
Overline Note, then to reduction of the principal indebtedness evidenced
thereby, and then to the other Promissory Notes as set forth in the Loan
Documents. After the occurrence of an Event of Default (other than an existing
Event of Default disclosed in EXHIBIT B to the Fourth Amendment) under the Loan,
and during the existence of any fact, circumstance or condition which, with
notice, or the passage of time, or both, might constitute an Event of Default
(other than an existing Event of Default disclosed in EXHIBIT B to the Fourth
Amendment) under the Loan Agreement or any of the other Loan Documents, the Bank
may apply all such payments as it may receive toward such of the Borrower's
indebtedness to the Bank as the Bank may determine in its sole and uncontrolled
discretion.

         3. No Further Loans or Advances, Extensions of Maturity Dates, etc. The
Borrower acknowledges that: (a) the Bank shall have no further obligation, under
the Loan Agreement or otherwise, to make any further loans or advances to or for
the benefit of the Borrower; (b) the Bank has extended the maturity date of the
Promissory Notes at the Borrower's request to give the Borrower additional time
to secure replacement financing sufficient to pay and discharge all of its
indebtedness and obligations to the Bank in excess of an amount to be
determined, but in no event to exceed ONE MILLION SIX HUNDRED THOUSAND AND
00/100 DOLLARS ($1,600,000.00), and the Bank has no obligation to grant further
extensions of time to the Borrower; and (c) no promise or agreement to grant any
such further extensions of time, or otherwise, shall be valid or enforceable
unless it is in writing and has been duly executed and delivered on behalf of
the Bank.

         4. Event of Default. Notwithstanding any provision of the Loan
Agreement or any Loan Document to the contrary, an Event of Default shall exist
under the Loan Agreement immediately upon default in making any payment when due
pursuant to the Loan Agreement or the pertinent Loan Documents, as amended by
this Seventh Amendment, without the necessity of giving Borrower notice or
opportunity to cure such default.

         5. Borrower's Representations, Warranties, Reaffirmations, etc. The
Borrower restates, affirms and makes, as of the date of this Seventh Amendment,
each of the covenants, agreements, acknowledgments, representations, warranties,
waivers and releases contained in the Loan Agreement and the other Loan
Documents. Further, except as specifically modified hereby, the Borrower
ratifies and affirms the continuing validity and binding effect of the Loan
Agreement and the other Loan Documents, and represents and warrants to the Bank
that all representations and warranties contained in the Loan Agreement and each
of the other Loan Documents are true as of the date hereof. The Borrower
represents and warrants that each balance sheet, statement of income, statement
of retained earnings and statement of changes in financial position submitted to
the Bank present fairly the financial position of the Borrower as of the date of
such statement. No changes having a material adverse effect upon any obligor for



                                       2
<PAGE>

any existing loans by the Bank to the Borrower have occurred since the date of
the most recent of such financial statements.

         6. No Existing Event of Default. The Borrower represents and warrants
to the Bank that, unless otherwise disclosed in EXHIBIT B to the Fourth
Amendment, there exists as of the date of this Seventh Amendment (a) no Event of
Default under the Loan Agreement or any of the other Loan Documents and (b) no
fact, circumstance or condition which, with notice, or the passage of time, or
both, might constitute an Event of Default under the Loan Agreement or any of
the other Loan Documents.

         7. Effect of this Seventh Amendment. The Loan Documents are hereby
amended as required (and only as required) to give effect to the amendments
expressly provided for in this Seventh Amendment. Each of the Loan Documents
shall be deemed to have been amended by this Seventh Amendment as if such Loan
Document had been specifically amended by separate instrument. This Seventh
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 hereby.

         8. Incorporation of Background Statement. The Background Statement is
incorporated into and forms a part of this Seventh Amendment.

         9. No other Amendments, etc. Except as expressly set forth above, the
Loan Agreement, each of the Promissory Notes, and all of the other Loan
Documents shall remain in full force and effect as originally executed and
delivered and subsequently amended by the parties, and are hereby ratified and
affirmed by the undersigned. Nothing in this Seventh Amendment shall release,
discharge or otherwise affect any security interests granted by the Borrower to
the Bank as collateral for the Borrower's indebtedness to the Bank, and the
Bank's rights and remedies with respect to any such security interests shall not
be diminished or impaired in any respect by this Seventh Amendment.

         10. Counterparts. This Seventh Amendment may be executed in one or more
counterparts, each of which shall be considered an original and all of which
shall constitute the same instrument.


                 [SIGNATURES APPEAR ON FOLLOWING PAGE; REMAINDER
                     OF THIS PAGE INTENTIONALLY LEFT BLANK]





                                       3
<PAGE>


                      [SIGNATURE PAGE TO SEVENTH AMENDMENT
                               TO LOAN DOCUMENTS]


         IN WITNESS WHEREOF, the parties have executed this Seventh Amendment to
Loan Documents as of the date set forth in the introductory paragraph on page 1.


WITNESSES:



_____________________________            RIVIERA TOOL COMPANY



_____________________________            By: /s/ Peter C. Canepa
                                             _________________________________
                                             Peter C. Canepa, Chief Financial
                                             Officer



_____________________________            FIFTH THIRD BANK



_____________________________            By: ___________________________________





                                       4