<PAGE>

                                                                    EXHIBIT 10.1

                        A G R E E M E N T  O F  S A L E

The undersigned, hereinafter designated as the Purchaser, hereby offers and
agrees to purchase land and premises situated in the City of Dearborn, County of
Wayne, State of Michigan described as follows: Full legal description to be
furnished by Seller at time of delivery of title commitment: more commonly known
as: 10200 Ford Road.

Together with all improvements and appurtenances, if any; and to pay therefore
the sum of:

         FOUR HUNDRED FIFTY THOUSAND AND 00/100 ($450,000.00) DOLLARS

                THIS SALE IS TO BE CONSUMMATED BY NEW MORTGAGE:
                -----------------------------------------------

     1.   The delivery of the usual Warranty Deed conveying a marketable title,
subject to Purchaser's ability to obtain an acceptable mortgage from a financial
institution of Purchaser's choice. Additionally, delivery of a Bill of Sale and
any other conveyancing documents with respect to systems in place as of August
30, 1999, as shown in Exhibit I.

                         COMMITMENT FOR TITLE POLICY:
                         ----------------------------

     2.   The Seller shall deliver to the Purchaser as soon as the contingency
period expires, a complete commitment for a policy of title insurance issued by
Land America-National Division, Troy, Michigan for an amount not less than the
purchase price hereunder, guaranteeing title in the condition required herein,
without standard exceptions and with such endorsements as may be required by
Purchaser's lending institution.

                    TIME OF CLOSING - PURCHASER'S DEFAULT:
                    --------------------------------------

     3.   If this Offer is accepted by the Seller, and if title can be conveyed
in the condition required hereunder, the Purchaser agrees to complete the sale
within thirty (30) days after waiver or completion of all contingencies.  In the
event of default by the Purchaser hereunder, the Seller may, as his sole remedy,
declare a forfeiture hereunder and retain the deposit as liquidated damages.

                     TITLE OBJECTIONS - SELLER'S DEFAULT:
                     ------------------------------------

     4.   If objection to the title is made, based upon a written opinion of
Purchaser's attorney that the title is not in the condition as required for
performance hereunder, the Seller shall have thirty (30) days from the date he
is notified in writing of the particular defects claimed, to either (1) remedy
the title; (2) obtain title insurance as required above; or (3) refund the
deposit in full termination of this Agreement if unable to remedy the tile or
obtain title insurance. If the Seller remedies the title or shall obtain such
title policy within the time specified, the Purchaser agrees to complete the
sale within ten (10) days of written notification thereof. If the Seller fails
to remedy the title or obtain such title insurance or to give the Purchaser the
above written notification within said thirty (30) days, the deposit shall be
refunded forthwith in full termination of this Agreement.
<PAGE>

                                  POSSESSION:
                                  -----------

     5.   The Seller shall deliver and the Purchaser shall accept possession of
said property at the time of closing, subject to the right of tenants as
follows:  No tenants unless mutually agreed to by Seller.

                                OWNER OCCUPIED:
                                ---------------

     6.   If the Seller occupies the property or any part thereof, it shall be
vacated on or before date of closing unless mutually agreed upon by Purchaser
and Seller, and deliver the premises in the condition required herein, with
Seller to properly remove and dispose of all equipment, stocks, scrap, debris,
etc.

                             ENCUMBRANCE REMOVAL:
                             --------------------

     7.   Any existing encumbrances upon the premises which the Seller is
required to remove under this Offer may be paid and discharged with the purchase
money at the time of the consummation of the sale, or if the Purchaser elects,
assumed with abatement of the purchase price.

                            TAXES; PRORATED ITEMS:
                            ----------------------

     8.   All taxes and assessments which have become a lien upon the land at
the date of this agreement shall be paid by the Seller except current taxes, if
any, shall be prorated and adjusted as of the date of closing. Taxes shall be
prorated on a due-date basis.

                            BROKER'S AUTHORIZATION:
                            -----------------------

     9.   The undersigned broker is hereby authorized to present this Offer to
the Seller and retain the deposit under the provisions of the statutes of the
State of Michigan.  The deposit money in the amount of Ten Thousand and 00/100
($10,000.00) Dollars, and shall be credited upon the purchase price if the sale
is completed.

                               ACCEPTANCE TIME:
                               ----------------

     10.  In consideration of the Broker's assistance to the Purchaser in the
preparation of this Offer and of his presentation thereof for the Seller's
acceptance, the Purchaser agrees that this Offer is irrevocable for five (5)
days from the date hereof, and if it is not accepted by the Seller within that
time, the deposit shall be returned forthwith to the Purchaser.

                                CLOSING PLACE:
                                --------------

     11.  The closing of this sale shall take place at the office of the
undersigned broker, or at a mutually acceptable location.

                                       2
<PAGE>

                                   NOTICES:
                                   --------

     12.  All notices, deliveries or tenders given or made in connection
herewith shall be deemed completed and legally sufficient, if mailed or
delivered to the respective party for whom the same is intended at his address
herein set forth.

     13.  Payment of the purchase money shall be made at closing in cash or
certified check.

     14.  The pronouns and relative words herein used are written in the
masculine and singular only. If more than one join in the execution hereof as
Seller or Purchaser, or either be of the feminine sex or a corporation, such
words shall be read as if written in plural, feminine or neuter, respectively.
The covenants herein shall bind the heirs, personal representative,
administrators, executors, assigns and successors of the respective parties.

                            ADDITIONAL CONDITIONS:
                            ----------------------

     15.  Purchaser shall have one hundred eighty (180) days after receipt of
fully accepted Offer (the "contingency period") to inspect and obtain the
following items, at Purchaser's sole and absolute discretion:

          a.   An acceptable mortgage commitment from a financial institution of
               Purchaser's choice.

          b.   Purchaser's physical inspection and satisfaction in its sole
               discretion of all aspects of the Property.

          c.   Purchaser's satisfaction with the results of an Environmental
               investigation of the Property. Seller will reimburse Purchaser
               for fifty percent (50%) of the cost to obtain a Baseline
               Environmental Assessment (BEA) approved by the MDEQ and
               satisfying Purchaser's "due care" obligations. The BEA contract
               and the consulting firm must be approved by both parties to this
               agreement.

          d.   Purchaser's satisfaction that the governing municipalities will
               allow the property to be used for Purchaser's intended use.

          e.   Purchaser accepts the building and property "as is," except that
               Seller agrees to:

               i)   Property backfill and install satisfactory concrete surface
                    over pit;
               ii)  Power wash and otherwise clean all floors, walls, blacktop
                    and pads to standards recommended by the environmental
                    consultant providing the BEA;

                                       3
<PAGE>

               iii) Repair office air conditioning systems; and
               iv)  Remove all tanks, equipment, tools, furniture, scrap and
                    debris, etc. from the premises except for the Clever-Brooks
                    Boiler, in conformance with applicable environmental
                    regulations, and except for items listed in Exhibit I.

          f.   Purchaser's receipt of all necessary Certificates of Occupancy
               for its intended use.

If Purchaser is unable to satisfy himself of the contingencies, at Purchaser's
sole discretion outlined in Subparagraphs (a) thru (f) inclusive, he shall
notify Seller in writing within the time limits set forth and this Purchase
Agreement shall be terminated and no longer in effect, all deposit monies shall
be refunded to the Purchaser forthwith, and the parties hereto shall have no
further obligation or liabilities to the other.

     16.  Seller represents and warrants that there are no pending or existing
lawsuits other than disclosed in Section 27 of this Agreement and is not aware
of any lawsuits or litigation covering the subject property and further holds
Purchaser harmless from the same.

     17.  Seller to supply, at his sole cost and expense, an ALTA survey of the
subject property showing all easements and structures of the subject property,
as certified to Purchaser, its lending institution and the title company.  Said
survey to be delivered to purchaser no later than forty-five (45) days prior to
closing.

                               "SUPERFUND" ACT:
                               ----------------

     18.  To the best of Seller's knowledge, no adverse environmental conditions
exist except with respect to items delineated in the Environmental Consulting &
Technology, Inc. environmental report issued as of May 3, 1993.  Seller agrees
to indemnify and hold Purchaser harmless of, from and against any and all loss,
liabilities, costs, damage or expense, including reasonable attorney's fees,
resulting from a breach of any warranty or misrepresentation under this Section
18, which indemnity shall survive the closing of this Agreement.

It is further understood and agreed that Signature Associates has made no
representation as to any hazardous and/or toxic waste issues, and both parties
hereby release Signature Associates from any liability.

                                REPRESENTATION:
                                ---------------

     19.  Seller warrants and represents that it has the authority to accept
this Agreement of Sale and that it now holds the title to the property to be
conveyed.

                             ADDITIONAL DOCUMENTS:
                             ---------------------

                                       4
<PAGE>

     20.  Each party agrees to execute any additional documents reasonably
requested by the other to carry out the intent of this Agreement.

                      HOLD HARMLESS AND INDEMNIFICATION:
                      ----------------------------------

     21.  The Purchaser agrees to indemnify and hold Seller harmless from any
claims, suits, damages, costs, losses and any expense resulting from and out of
Purchaser's or its officers, directors, agents and/or employees occupancy,
possession, use and ownership of the property herein during the time the
Purchase Agreement is in existence. The Seller agrees to indemnify and hold
Purchaser harmless from any claims, suits, damages, costs, losses and any
expenses resulting from and arising from and out of the negligence of its
officers, directors, agents and/or employees during the time the Purchase
Agreement is in existence due to negligence of its officers, directors, agents
and/or employees.

                  SURVIVAL OF REPRESENTATION AND WARRANTIES:
                  ------------------------------------------

     22.  The representations and warranties as set forth in this Agreement
shall be continuing and survive the Closing.

                            DATE OF THIS AGREEMENT:
                            -----------------------

     23.  For purposes of the transaction contemplated by this Agreement, the
"Date of this Agreement" is the date of acknowledgment of the signature of the
last party to sign this Agreement.

                                   HEADINGS:
                                   ---------

     24.  The headings of this Agreement are for purposes of reference only and
shall not limit or define the meaning of the provisions of this Agreement.

                       SATURDAYS, SUNDAYS AND HOLIDAYS:
                       --------------------------------

     25.  Whenever in this Agreement it is provided that notice must be given or
an act performed or payment made on a certain date, and if such date falls on a
Saturday, Sunday or holiday, the date of the notice of performance or payment
shall be the next following business day.

                                    WAIVER:
                                    -------

     26.  No waiver of any of the provisions of this Agreement shall be deemed
or shall constitute a waiver of any other provisions, whether or not similar,
nor shall any waiver be a continuing waiver. No waiver shall be binding unless
executed in writing by the party making the waiver.

                                       5
<PAGE>

                            NO ADVERSE INFORMATION:
                            -----------------------

     27.  Seller shall provide summaries of judicial proceedings to Purchaser
within ten (10) days of the date of the Purchase Agreement and Seller shall pay
all sums due and obtain all appropriate discharges at/or prior to closing.

                                EMINENT DOMAIN:
                                ---------------

     28.  If before closing all or any part of the real estate is taken by
eminent domain, Purchaser may terminate this Agreement. If Purchaser terminates,
neither Seller nor Purchaser shall have any further obligation to the other and
the earnest money deposit will be promptly returned to Purchaser. If Purchaser
does not terminate, this Agreement will remain in effect and Seller will assign
to Purchaser all of Seller's rights to received any awards that may be made for
such taking.

                                 COOPERATION:
                                 ------------

     29.  The parties hereto agree to cooperate with each other in every
reasonable way in carrying out the transaction contemplated hereby, in obtaining
and delivering all required closing documents.

                                     RISK:
                                     -----

     30.  All risk of loss or damage to the property shall be upon Seller until
closing is made therefore.

                                    ACCESS:
                                    -------

     31.  Seller represents and warrants that there exists access to the
Premises for vehicular and pedestrian ingress and egress from public roads and
there does not exist any fact or condition which would result in the termination
or impairment of that access.

     32.  This offer to Purchase has been prepared for submission to your
attorneys for approval. No representation or recommendation is made by Signature
Associates as to the legal sufficiency, legal effect or tax consequences of this
Offer to Purchase or the transaction relating thereto; the parties shall rely
solely upon the advice of their own legal counsel as to the legal and tax
consequences of this Offer to Purchase. All Purchasers of real estate should
have their title examined by an attorney.

     33.  The Purchaser and Seller agree that the Broker and/or Real Estate
Agent has fully disclosed any knowledge that he has or should have concerning
possible toxic and hazardous material or substance on or about the subject
property, and the purchaser acknowledges that he has made a competent inspection
of the property or that he has been given the opportunity to make a competent
inspection, and the Purchaser and Seller do hereby release the Broker and/or
Real Estate Agent from any liability concerning toxic and hazardous material or
substance on

                                       6
<PAGE>

said subject property. The Purchaser and Seller, each hereby expressly waive any
claim whatsoever against the Broker and/or Real Estate Agent before or after the
closing of this transaction arising out of or in connection with any of the
foregoing.


IN THE PRESENCE OF:           PURCHASER: DEMONTE FABRICATING, LTD.


________________________      By:  /s/ Walter P. DeMonte
                                  -------------------------
                                       Walter P. DeMonte

________________________      Its:  President
                                  -------------------------

Date: 9/7/99   Address: 4975 8 Concession Road, RR# Maidstone, Ontario, N0R 1K0,
      ------            --------------------------------------------------------
Canada
------



                      BROKER'S ACKNOWLEDGMENT OF DEPOSIT:
                      -----------------------------------

Received from the above named Purchaser the deposit money above mentioned which
will be returned forthwith if the foregoing Offer is not accepted within the
time above set forth.

Signature Associates, Inc., One Towne Square, Suite 1209, Southfield, Michigan
48076 (248) 948-9000

                                    By:  /s/ Brad M. Viergever
                                         ---------------------
                                             Brad M. Viergever

                                    Its: Associate Broker
                                         ----------------

                                       7
<PAGE>

                             ACCEPTANCE OF OFFER:
                             --------------------

TO THE ABOVE NAMED PURCHASER AND BROKER

The foregoing Offer is hereby accepted and the Seller agrees to sell said
premises upon the terms stated.

The Seller hereby agrees to pay the Broker for services rendered and for value
received a commission of six (6%) percent of the sale price, which shall be due
and payable upon the consummation of the sale.  If the sale is unconsummated, as
a result of Seller's or Purchaser's failure, inability or refusal to perform the
conditions of this Offer, and the deposit is forfeited to the Seller under the
terms of said offer, the Seller agrees that one-half of such deposit (but not in
excess of the amount of the full commission) shall be paid to or retained by the
Broker in full payment for services rendered.

By the execution of this instrument, the Seller acknowledges the receipt of a
copy of this Agreement.

IN THE PRESENCE OF:                      SELLER:

                                         By:  /s/ Robert W. Truxell
__________________________                    -------------------------
                                                  Robert W. Truxell

__________________________               Its:  Chairman
                                              -------------------------

Date: 9/8/99     Address:  10200 Ford Road, Dearborn, Michigan 48126
     -------               --------------------------------------------


                    PURCHASER'S RECEIPT OF ACCEPTED OFFER:
                    --------------------------------------

The Purchaser hereby acknowledges the receipt of the Seller's signed acceptance
of the foregoing Offer to Purchase.

                              PURCHASER: DEMONTE FABRICATING, LTD.


Date: 9/13/99                 By:  /s/ Walter P. DeMonte
     --------                      ------------------------------------
                                       Walter P. DeMonte

                                       8