Working with old maps is such an individualized cut out process. I can't use a pencil on the back of the map because I want to be able to determine exactly where my blade should cut based solely on the content of the map. I cut maps by freehand to be able to work with or around (depending on my goal) the specific elements and graphics of the sheet I'm working with.
I have always loved maps and used them for variety of projects - envelopes, cards, decoupage. PaperCutWorks on etsy now features several wooden blocks displaying map heart cut outs.
As with all my cut outs, each heart is very unique & is never recreated. I have a large stash of old outdated maps and can create a custom piece featuring a specific city, state, province, sea, ocean, river, mountain range.
Wooden blocks make unique gifts & sturdy decor pieces - you can display them sitting on a shelf or hanging on the wall. The cradled birch block frames I use measure 4" by 4" or 5" by 5" and are1.5" thick.
Mounting paper hearts on the wood block makes the piece more durable, but also allows me to give the protective sealant painting-like finish by using brush strokes.