How to copy similar images from one FM book to another FM book?

Assuming you've referenced the graphics in the first file … you can copy/paste into the new file; you could create a list of referenced graphics (LOF) to help you locate the graphics in the first book more easily. Or, depending on the content of the two books, you could duplicate .fm chapters from the first book and rewrite the text round the graphics :-}

Scripting is unexplored territory for me, but I imagine it should be possible to type in just the name of each graphics files and then use a script to do the work of setting up the reference?