A project like that would go better with a ready supply of replacement parts (and decent tools). Do you have access to a bike co-op?

I recently rebuilt two early 80s Treks, a 520 and a 620, upgraded both to 8-speed rears, newer triple cranksets and bottom brackets, with salvaged 3x8 brifters and salvaged compatible derailleurs. The co-op parts bins made it work. Both of those bikes came with Maillard Helicomatic cassette hubs, which had to be replaced. Cold-setting the frames to 130 mm was easy with the co-op tools and gauges.