<PAGE>
                                                                   Exhibit 10.63


        FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT

         This Fourth Amendment to Second Amended and Restated Credit Agreement
(herein, the "Amendment") is made as of December 23, 2005, by and among Morton
Industrial Group, Inc., a Georgia corporation (the "Borrower"), the Lenders
party to the Credit Agreement hereinafter identified and defined, and Harris
N.A., successor by merger to Harris Trust and Savings Bank, as Agent for the
Lenders (in such capacity, the "Agent").

                                    RECITALS

          A. The Lenders currently extend credit to the Borrower on the terms
and conditions set forth in that certain Second Amended and Restated Credit
Agreement dated as of March 26, 2004, as amended, by and among the Borrower, the
Guarantors, the Lenders and the Agent (the "Credit Agreement"). All capitalized
terms used herein without definition shall have the same meanings herein as such
terms have in the Credit Agreement.

         B. The Borrower has requested that the Lenders modify the Fixed Charge
Coverage Ratio for the fiscal quarter ended December 31, 2005 and the Capital
Expenditures limitation for the fiscal year 2005, and the Lenders are willing to
do so on the terms and conditions set forth in this Amendment.

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

SECTION 1. AMENDMENTS.

         Subject to the satisfaction of the conditions precedent set forth in
Section 2 below, the Credit Agreement shall be and hereby is amended as follows:

         1.1. Section 5.1 of the Credit Agreement is hereby amended by amending
and restating the definition of "Excess Cash Flow" set forth therein to read in
its entirety as follows:

                  "Excess Cash Flow" means, with respect to any period, the
         amount (if any) by which (a) EBITDA for such period exceeds (b) the sum
         of (i) Interest Expense payable in cash during such period, plus (ii)
         federal, state and local income taxes payable in cash during such
         period, plus (iii) the aggregate amount of payments required to be made
         by the Borrower and its Subsidiaries during such period in respect of
         all principal on all Indebtedness (whether at maturity, as a result of
         mandatory sinking fund redemption, mandatory prepayment, acceleration
         or otherwise, but excluding payments made under the Revolving Credit
         and excluding mandatory prepayments of the Term Loans required to be
         paid in respect of Excess Cash Flow under Section 3.3(a) hereof) and
         all payments of Indebtedness of the type described in clause (viii) of
         the definition of "Indebtedness" herein, plus (iv) the aggregate amount
         of Capital Expenditures made by the Borrower and its Subsidiaries
         during such period to the extent


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         permitted by this Agreement and not financed with proceeds of
         Indebtedness, provided that, for the fiscal year of the Borrower ending
         December 31, 2005 only, the aggregate amount of Capital Expenditures
         made by the Borrower and its Subsidiaries during such fiscal year shall
         be deemed by the parties hereto to be $5,500,000 for the purposes of
         calculating the amount of Excess Cash Flow for such fiscal year,
         notwithstanding the actual amount of Capital Expenditures made by such
         parties during such period.

         1.2. Section 8.9 of the Credit Agreement is hereby amended and restated
to read in its entirety as follows:

                   Section 8.9. Fixed Charge Coverage Ratio. The Borrower will
         not, as of the last day of each fiscal quarter of the Borrower ending
         on the dates set forth below, permit the Fixed Charge Coverage Ratio to
         be less than:

<TABLE>
<CAPTION>
                                                     FIXED CHARGE COVERAGE RATIO
FISCAL QUARTER ENDING DATES                           SHALL NOT BE LESS THAN
<S>                                                  <C>
         12/31/05                                            1.05 to 1.0
All fiscal quarter ending dates                              1.15 to 1.0
       thereafter
</TABLE>


         1.3. Section 8.10 of the Credit Agreement is hereby amended by deleting
the amount "$5,500,000" for fiscal year 2005 and replacing it with the amount
"$7,000,000."

SECTION 2. CONDITIONS PRECEDENT.

         The effectiveness of this Amendment is subject to the satisfaction of
all of the following conditions precedent:

                  2.1. The Borrower, the Agent, the Required Lenders and the
         Guarantors shall have executed and delivered this Amendment.

                  2.2. Legal matters incident to the execution and delivery of
         this Amendment shall be satisfactory to the Agent and its counsel.

                  2.3. The Agent shall have received a certified copy of an
         amendment to the Note and Warrant Purchase Agreement increasing the
         capital expenditures limitation covenant therein to an amount not less
         than $7,000,000 for fiscal year 2005 and which shall otherwise be in
         form and substance acceptable to the Agent.

                  2.4. The Borrower shall have paid to the Agent, for the
         benefit of the Lenders, an amendment fee in the amount of $2500 per
         Lender.

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SECTION 3. REPRESENTATIONS.

         In order to induce the Lenders to execute and deliver this Amendment,
the Borrower hereby represents to the Lenders that as of the date hereof, and
after giving effect to this Amendment, (a) the representations and warranties
set forth in Section 6 of the Credit Agreement are and shall be and remain true
and correct in all material respects (except that for purposes of this paragraph
the representations contained in Section 6.5 shall be deemed to refer to the
most recent financial statements of the Borrower delivered to the Lenders) and
(b) the Borrower is in full compliance with all of the terms and conditions of
the Credit Agreement after giving effect to this Amendment and no Default or
Event of Default has occurred and is continuing under the Credit Agreement or
shall result after giving effect to this Amendment.

SECTION 4. MISCELLANEOUS.

         4.1. The Borrower and certain of its Subsidiaries have heretofore
executed and delivered to the Agent and the Lenders certain of the Collateral
Documents. The Borrower hereby acknowledges and agrees that, notwithstanding the
execution and delivery of this Amendment, the Collateral Documents remain in
full force and effect and the rights and remedies of the Agent and the Lenders
thereunder, the obligations of the Borrower and its Subsidiaries thereunder, and
the liens and security interests created and provided for thereunder remain in
full force and effect and shall not be affected, impaired, or discharged hereby.
Nothing herein contained shall in any manner affect or impair the priority of
the liens and security interests created and provided for by the Collateral
Documents as to the indebtedness which would be secured thereby prior to giving
effect to this Amendment.

         4.2. Except as specifically amended herein or waived hereby, the Credit
Agreement shall continue in full force and effect in accordance with its
original terms. Reference to this specific Amendment need not be made in the
Credit Agreement, the Notes, or any other instrument or document executed in
connection therewith, or in any certificate, letter or communication issued or
made pursuant to or with respect to the Credit Agreement, any reference in any
of such items to the Credit Agreement being sufficient to refer to the Credit
Agreement as amended hereby.

         4.3. The Borrower agrees to pay all reasonable out-of-pocket costs and
expenses incurred by the Agent and the Lenders in connection with the
preparation, execution and delivery of this Amendment and the documents and
transactions contemplated hereby, including the reasonable fees and expenses of
counsel for the Agent with respect to the foregoing.

         4.4. This Amendment may be executed in any number of counterparts, and
by the different parties on different counterpart signature pages, all of which
taken together shall constitute one and the same agreement. Any of the parties
hereto may execute this Amendment by signing any such counterpart and each of
such counterparts shall for all purposes be deemed to be an original. This
Amendment shall be governed by the internal laws of the State of Illinois.


                           [SIGNATURE PAGES TO FOLLOW]


                                      -3-


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         This Fourth Amendment to Second Amended and Restated Credit Agreement
is entered into by the parties hereto as of the date and year first above
written.

                                         MORTON INDUSTRIAL GROUP, INC.


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------

                                         Accepted and agreed to:

                                         HARRIS N.A., successor by merger to
                                           Harris Trust And Savings Bank


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------

                                         NATIONAL CITY BANK OF THE MIDWEST


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------


                                         JPMORGAN CHASE BANK, N.A.
                                           (formerly known as Bank One, N.A.)


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------


                                      -4-
<PAGE>

                     GUARANTORS' ACKNOWLEDGEMENT AND CONSENT

         Each of the undersigned hereby acknowledges and agrees that it is a
Guarantor under the terms of Section 11 of the Credit Agreement and, as such,
has executed and delivered certain Collateral Documents pursuant to the Credit
Agreement. The undersigned hereby consent to the Fourth Amendment to Second
Amended and Restated Credit Agreement as set forth above and agree to the terms
thereof, and the undersigned hereby confirm that their guaranties and the
Collateral Documents executed by them, and all of the obligations of the
undersigned thereunder, remain in full force and effect. The undersigned further
agree that the consent of the undersigned to any further amendments to the
Credit Agreement shall not be required as a result of this consent having been
obtained. The undersigned acknowledge the Lenders are relying on this
acknowledgement and consent in entering into the Fourth Amendment to Second
Amended and Restated Credit Agreement with the Borrower.


                                         MORTON METALCRAFT CO.


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------


                                         MORTON METALCRAFT CO. OF NORTH CAROLINA


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------


                                         MORTON METALCRAFT CO. OF SOUTH CAROLINA


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------


                                         MID CENTRAL PLASTICS, INC.


                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------


<PAGE>




                                         B&W METAL FABRICATORS, INC.

                                         By
                                           Name
                                               ---------------------------------
                                           Title
                                                --------------------------------



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