I've got a 1979 Hi-Ten bike (sold by JC Penney & gutted, rebuilt by me) and a 1982 Colnago that I ride all the time. Upkeep is -0- problem with either: Ebay and www.bikepartsusa.com have anything I might need for the Hi-Ten ... including both brand new 27" and 700c wheels with/screw-on freewheel threads; The Colnago is a modern Campy brifter set-up, so the only thing "unmodern" about it are the lugs and about 1.5 extra pounds from that 9-6-9 & 9-7-9 tubing .

Sometimes you'll find an old-time roadie at a shop who's squirreled away the older parts, but at most bike stores you'll hear, "Have you tried Ebay?" -- which is almost always the best option, IMO. It's amazing how much new-old-stock is in circulation out there ... just don't expect bargains on NOS high-end 70s & 80s Campy, which goes for way more than when it was new.