I don't know about the 70s Palo Alto frames, but I believe many of the 80s frames with Columbus tubing were built by Romani. I would think that a check of the threading for the bb would be a good indication as I believe the Romani built frames had Italian threading, although I don't know what type of bb threading Tom Ritchey would have used. Here is the information I have from the Used Bike Buyers Guide on Romani. Lou Deeter, Orlando FL
ROMANI: Via Are, 12-43038 Sala Baganza, Parma, Italy 011-39-521-833146. Currently, Rodolfo &Gaetano Romani. Since 1924. Columbus & Oria tubing.