That Cinelli is a NICE bike. If not original, the paint is very well done. Definitely not one of those overdone dipped in clear jobs. I agree maybe an early '70's and not late '60's. (I have a late '60's bike that has fender eyelets and fender mounting lugs, drilled lugs, but no drillings in the fork tangs, also, no braze on cable guides)
Also, my original paint 1970 (approximate) SC for comparison:
http://www.wooljersey.com/
I would consider letting it go for half the price of the E-bay bike ;)
Jeff Pyzyk
Milwaukee, WI