My friend recently donated an enormous, wonderfully cared-for collection of SNES RPGs to me, including a bunch of mint condition maps and posters.
Flattening them out won't harm them, right? They'll refold okay? I'd love to contribute.
Off the top of my head there's... two different Chrono Trigger sheets, Actraiser, Final Fantasy 6, Illusion of Gaia, and more.