I stumbled upon Yesterland.com the other day, and I've been really enjoying reading up on the site and exploring it.
I'm a bit of a map geek. Don't really know why, but I really enjoy pouring over maps, especially historic maps (such as old railroad maps of my city) to see how things have changed over time.
I'm sure the logistics of gathering source material would be difficult, but I think it'd be very interesting if Yesterland could obtain and provide some high resolution scans of different versions of the park maps handed out to guests over the years.
Might make for a neat section of the site. Keep up the good work!