By the 1990s, Campag were offering several group sets in different quality and price ranges, for both racing and touring.
Trusting the information of a single component, when determining a bicycle's vintage, is not a good idea.
Excluding the aero pedals launched in 1983, we are working on a seperate blogpost about those beauties.
As you know, Campagnolo was not always transparant about the exact production dates of parts.
As the wear on a vintage bike increases, the greater the likelihood components are not original, either through replacement of worn parts or through component swaps.
Swaps can take place early in the life of a bike as the proud new owner upgrades to new or used components of higher quality.