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                                                                     Exhibit 4.2

                        JOINDER TO REGISTRATION AGREEMENT

         THIS JOINDER TO REGISTRATION AGREEMENT (this "Joinder") is executed as
of March 28, 2003, by and among Bostrom Holding, Inc., a Delaware corporation
(the "Company"), J2R Partners VI ("J2R"), CVS Partners, LP ("CVS Partners"), and
CVS Executive Investco LLC ("Investco" together with J2R and CVS Partners, the
"New Investors").

         WHEREAS, the Company, Onex Corporation, J2R Partners VII and certain
other stockholders of the Company are party to that certain Registration
Agreement, dated as of October 5, 2000, as amended (the "Registration
Agreement"). Capitalized terms used but not defined herein have the meaning
given to them in the Registration Agreement.

         WHEREAS, the New Investors have acquired shares in the Company pursuant
to that certain Agreement and Plan of Merger, dated even herewith, by and
between the Company, CVS Merger Co., and CVS Holdings, Inc.

         WHEREAS, the Company desires to provide the New Investors rights under
the Registration Agreement as set forth herein.

         NOW, THEREFORE, the parties hereto agree as follows:

         1.       Joinder. The parties hereto agree that, by and upon execution
of this Joinder, each New Investor shall be a party to the Registration
Agreement, (ii) shall be an "Investor" (as such term is defined in the
Registration Agreement) and (iii) shall be entitled to the rights and benefits
and subject to the duties and obligations of an Investor thereunder, as fully as
if such New Investor had been an original signatory thereto in such capacity.

         2.       Continuing Effect. Other than as modified in accordance with
the foregoing provisions, the remaining terms of the Registration Agreement
remain in full force and effect.

         3.       Counterparts. This Joinder may be executed in separate
counterparts each of which shall be an original and all of which taken together
shall constitute one and the same agreement.

         4.       Governing Law. All questions concerning the construction,
validity and interpretation of this Joinder shall be governed by and construed
in accordance with the internal laws, and not the law of conflicts, of Delaware.

         5.       Descriptive Headings. The descriptive headings of this
Agreement are inserted for convenience only and do not constitute a part of this
Agreement.

                                    * * * * *

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         IN WITNESS WHEREOF, this Joinder has been entered into as of the date
first above written.

                                                    BOSTROM HOLDING, INC.

                                                    By: /s/ Daniel Moorse
                                                        ------------------------
                                                    Name: Daniel Moorse
                                                         -----------------------
                                                    Its: Vice President
                                                         -----------------------

                                                    J2R PARTNERS VI

                                                    By: /s/ S. A. Johnson
                                                        ------------------------
                                                    Name: S. A. Johnson
                                                         -----------------------
                                                    Its: Managing Partner
                                                         -----------------------

                                                    CVS PARTNERS, LP

                                                    By: /s/ Eric Rosen
                                                        ------------------------
                                                    Name:
                                                         -----------------------
                                                    Its:
                                                         -----------------------

                                                    CVS EXECUTIVE INVESTCO LLC

                                                    By: /s/ Eric Rosen
                                                        ------------------------
                                                    Name:
                                                         -----------------------
                                                    Its:
                                                         -----------------------