I didn’t read all of it but they do talk a bit about woodcuts. That was a hobby of mine for a while. It’s where you carve a “stamp” into a piece of wood.

They were cutting up printed images and pasting them together, in a process commonly known as “collage”.

Was the final manuscript glued together then? If so, this whole article seems off-point. Why not just say "this old manuscript has images made up of several layers, it looks like collage"?

I was assuming this college technique was used to make a (plan for a) new woodcutting.

Edit:college -> collage

Yeah the decision to never say “collage” even once is a strange one. It looks like the glued-up piece is the final manuscript to me.