Dunno: the seller may call it a San Cristobal, but this is clearly a late frame built by the (very competent) contractors who bought out the Ciocc name from Giovanni Pellizoli. It has internal cable routing and a Cromor tubing decal...same sort of seat cluster as on my own "late" Ciocc which is also contract-built and from the early '90s. Maybe that fork is original (and if so might have Cromor blades) it appears to have the word Ciocc at an angle, which is similar to the panto on my "late" Ciocc fork, but that crown style is different to mine.
My other Ciocc is a genuine San Cristobal from the early days and was hand-built by Giovanni himself, and the difference is quite apparent. They are both very nice bikes, but the earlier frame is very nicer