backing up icons

What is the format of your Icons? Is this *.ico or *.png?

Generally you can set the option "Save with toolbar" when you select the icon, but if this is existing toolbar with many shortcuts then that is problem TLB doesn't backup icons that was not saved with toolbar.

Also the "Save with toolbar" works with "single file icons" like *.ico or *.png and not working for icons from dll/exe.

For icons that were not saved with toolbar - TLB will not find them if you move icons to other location. And there are not build in tools to to something with this. But it is possible to change location directly in tlbdata.xml files. These files can be found in toolbar folder. The files are have text format (XML) and even Notepad++ can be used to replace old path to the new in all files.

Refresh toolbar after changing tlbdata.xml