As far as I understood it from Anton's blog, the current construction is taking place at Ryan's house somewhere in California (also see the Californian "PHOTOP" license plate they acquired for The Photo Palace bus). Anton moved up there since they had a full mechanical workshop out there available to do the necessary work.
I don't know them personally, but donated to the project (which still can be done here), as I think it is great.
Don't know the exact route they will be following, but I guess you can always drop Anton an e-mail to figure it out or arrange something. They developed the concept just for that: teaming and meeting up with fellow analog photographers or interested people, and shooting a comprehensive series of portraits and photos throughout the entire U.S.