I have upgraded this solution to include the missing image files, updated the manifest and modified ColumnManager.aspx to use correctly named paths.
- Add IMAGES\ColumnManager and include missing images (minu.gif, plus.gif) which already exist in 12\TEMPLATE\IMAGES\.
- Update manifest.xml and add the following to <TemplateFiles> section.
<TemplateFile Location="IMAGES\ColumnManager\plus.gif" />
<TemplateFile Location="IMAGES\ColumnManager\minus.gif" />
- Modify ColumnManager.aspx and replace all bad paths to images.
i.e. images/ListManager/ = IMAGES/ColumnManager/
Repackage and run stsadm -o upgradesolution.
Happy to provide complete solution to anyoen who wants it.