Are you aware there is a free download of Migration related utilities for AutoCAD 2004?
The list of Migration Tools and descriptions:
Autodesk® Batch Drawing Converter 2004 converts any AutoCAD or AutoCAD-based drawing file to AutoCAD Release 14, AutoCAD 2000, AutoCAD 2000i, AutoCAD 2002, and AutoCAD 2004 file formats. Autodesk Batch Drawing Converter allows conversion of pen widths to lineweights and the addition of page setups. Note: Autodesk Batch Drawing Converter 2004 is available in Brazilian Portuguese, Simplified and Traditional Chinese, Czech, English, French, German, Hungarian, Italian, Japanese, Korean, Polish, Russian, and Spanish.
For AutoCAD 2004 and AutoCAD 2004–based products (except AutoCAD LT), these Autodesk® Customization Conversion tools allow you to convert your customized menus, files, command aliases, and layer states, and they allow you to script with greater ease.
AutoLISP Compatibility Analyzer details AutoCAD 2004 compatibility issues found in AutoLISP® and Menu LISP files. When an issue is found, an explanation of the compatibility issue and suggestions on how to correct it are provided.
In order to use many of these utilities, you will need AutoCAD 2004 installed as they use some of the files from the installed AutoCAD.