Hi, Yes it rides great and handles well and the paint condition is very good.
The Retinato paint scheme on the very thin seat tube is a classic colnago paint scheme of mid 80s I believe so it might be the original paint scheme after all.

I will though rebuild with super record groupset as the group set does not match the bike.
I have an Ofmega sprint colnago panto set however which might suit better or just leave as it is. However the fork is not standard colnago would like to find a masters or mexico form to swap.

I posted some extra pics for comparison with other early colnagos .. the blue colnago nuovo profili and the green a first generation mexico and a colnago saronni with no panto on the downtube lug (so it did happen sometimes). You will notice how thin the seat tube is. Also how flattened the chain stays are in comparison. The back end is more like first generation colnago. Also the routing of the cables is odd at the back it exists from the other side than expected at the back end.

There just seems too many modifications BB/tubes that there must be a record of it somewhere.