I like the scrapbook idea; maybe there could be a third button next to "sign" and "done" called "sketch", where it would take whatever the player's looking at (minus hotbar and the book interface itself) and generate a line drawing, kind of like one of the Super Secret Settings. Since it's a book and quill (using ink), this would give the feel of your player actually sketching the image.
you start writing a book an quill, and then craft the unfinished book with a map, to add it to the first area in the book that has space for the map.
then you can continue writing the book after, and then finally sign it.
does that seem more vanilla-esc to you?
Its probably better if the player gets to choose where they want to put their map. The OP's way is better. Also look at my post which I think would work well. How is crafting vanilla-esc? What's the point of making everything by crafting. Very unoriginal, boring, etc.