I live about an hour from Allentown and I see a lot of Rosses here. Usually they're junk, with seatstay "plates" rather than bridges (Definite giveaway!), but yesterday I saw a Signature at the local Salivation Army. Real nice stuff, but unfortunately it was too small for me.
I think the higher end stuff was built by a local custom framebuilder, and he may have chosen the tubing himself. I can't recall his name.