Wed Apr 09 2014 14:21:44 GMT-0700 (PDT) @maxolson:
The USSR map is now merged into the base-map, and initial admin-1 maps for Western Europe are up (with the breakup of Yugoslavia).
We are starting by working backwards from the modern boundaries, as it's easier to work from the current base.
Speaking of which, I just added a Best Practices
document to the Github repo. Feel free to add to or edit this with any best practices you encounter while making history maps.