I'd like to see a better photo of the track ends and the brake bridge. Looking at the fork, it does appear to be a track frame, so a proper resto would be a track bike. Based on what little info is provided, specifically the panto info, I would venture to date this bike mid to late 70s. But I must say the track ends look decidedly crude. Is there any evidence of rifling inside the seat tube down near the BB? It is probably Columbus SL, rifling might indicate SLX, but the date I put on it makes it seem unlikely. Kind of miss my Guerc, but the Merck it got me is a sweet ride.