Colnago does not really have a history department. Guys who met with Ernesto in San Diego at the Granfondo a few years back commented that Ernesto likes to see the old bikes but does not really remember them in detail, it was about making money guys. From the BB shell and transfers, and BB shell which appears cast due to the thickness and style of Clover cutout, later 70's to very early 80's. The seat stay caps are atypical. That crown really shows up in the mid 70's, like 1975-76, but the graphics especially the head tube are later.