I couldn't afford a 'good' bike back in the 70's. It was already the early 80's before I could spend hungreds of dollars on a bike. By the time I started getting serious about riding fast, Shimano was making giant inroads into Campagnolo territory. The first 'custom' bike I had (and still have) was equipped with a mix of Dura Ace and Record, and as improvements came about, those bits were upgraded.
My 1984 Cinelli SC is a perfect example. It has Record seatpost & headset, DA AX BB and crank, with Dyna Drive pedals and Binda straps, DA 7400 dérailleurs coupled to 6 speed SIS levers. A jury rigged set of Dura Ace AX 36 hole cassette hubs, changed from 7 speed to 6 speed to work with the SIS laced to GP4's, with a set of 7400 32 hole hubs laced to GEL 280s for race day. Of course, there are Cinelli bars and stem. Dura Ace AX speed adjusters for slowing down power.
This setup would be/is considered sacrilegious to a collector, but it worked together real well when I actually tried to race, and still works well today. It is period correct.
I have recently bought a few 'collectable' bikes, and I'm always confused by the mix of parts on them. A couple of them I know were never changed from the day they were delivered, because I bought them from the original owners and they confirmed as much. Invariably they have born out caterham's theory/complaint/rant about 'period correctness'. Bikes that I know have not had a part changed on them have Campagnolo components that vary by 3-4 years on them. Newer shift levers with old seat posts, and crank arms that are 3 years older than the frame build date. It seems that Campagnolo, especially, could have a wide range of parts available at any one time and depending on the distributer and the dealer. You could have a 'new build' with a wide range of dates. I doubt if Tullio even knew what the latest model was! None of this seemed to matter back then, it's just something for collectors to obsess over today.
I know caterham rides every one of his bikes, I know Road Fan does too. That's the most important thing.
Forty years from now let someone else try to figure out how Road Fan's Mondonico came to have a 21st century drivetrain. I know it's because it makes it easier for him to ride it up the hills along the Huron River, and if it keeps him riding, that's a good thing.
Sorry for the long, rambling, post. It must be the Mother's fumes I've been inhaling all day.
John