I have 80s friction, and three sets of Syncro 6 speed (C Record Syncro and 2x C Record Syncro II, one NIB).
[edited with info from velobase]
Note that the latter are backward-compatible with earlier Campag mechs (Super Record, Nuovo Record, ...), and I have used them as such for many years (not the ones for sale, the ones still on my bike). They've always worked well for me with period Regina freewheels.
Nick