Were you ever able to date it? I just happened to stumble across some 1984 ads for the Palo Alto frames. They are similar to yours but not identical in that they have eyelets on the rear dropouts, a chromed fork chrome, no bottle bosses, derailleur cables routed above the bottom bracket and triangular cutouts on the side of the head lugs. In my opinion, all these features point to a model slighter older than yours. FWIW, advertised price for the frames was $325 US.