Book du jour - prototype for map transformation

Trying out the structure with the first map that came to hand, cut into 4"-square diamonds and glued into a soft cover -

The structure is from Alisa Golden's "Hundred Handmade Books" -

The local Oxfam bookshop usually has old OS maps, which have a plain back and will make an attractive book. The little pockets can hold ... what? Even though I'm thinking of making some out of old maps, I haven't figured out "why" - what's the actual idea, apart from having a pretty book. Still, there's nothing wrong with making a pretty little book...