You're right about the pantographing - a quick google image search showed only a couple of ciocc's that didn't have pantographed seatstays - and the fork crowns were all sloping ones with the 4-leafed clover containg card suits - so if it is a Ciocc it may be older than you think - or perhaps one of the lower-end italian-market jobs.
If Ciocc don't get back to you there's bound to be people posting serial#'s on the web - try searching for those
Why did the LBS think it's columbus? was it just the seatpin diameter not 27.2mm or do they have another way of determining it
You're right about the pantographing - a quick google image search showed only a couple of ciocc's that didn't have pantographed seatstays - and the fork crowns were all sloping ones with the 4-leafed clover containg card suits - so if it is a Ciocc it may be older than you think - or perhaps one of the lower-end italian-market jobs.
If Ciocc don't get back to you there's bound to be people posting serial#'s on the web - try searching for those
Why did the LBS think it's columbus? was it just the seatpin diameter not 27.2mm or do they have another way of determining it