More old maps
I don’t think I knew about this before (perhaps somebody mentioned it in the comments?), but there is a new website that serves as a portal for old maps in various libraries. It sends you to the host library interface, where most allow you to zoom in and pan around. Depending on the library, you may not be able to download the maps, but it does allow you to search for place names, and it looks like even small villages shown on maps are indexed, so that’s pretty powerful.
It’s OldMapsOnline, at http://project.oldmapsonline.org/collections.