Thing I learned from building Vintage bike up.
So today I finished my 1990 raleigh olympian up ( I say finished but lord knows I'll keep changing something) and these are the things I've learned during it.
Trying to take a vintage bike and make a good road worthy machine that can hold it's own against most group rides/non races is very do-able, scoring kom's on downtube shifters is a pain but possible. It's better to just buy a new bike unless you already have stuff laying around/ don't care about end cost.
I changed the stem,seat,crankset,wheelset,went from 6 speed downtube to 9 speed sti levers, dual pivot brakes, 9 speed chain, new 9 speed derailleur, and changed bottom bracket. With the help of a friend I have a bike I consider capable of keeping myself competitive in my B-class group rides with about 250$ spent total.
While I'm sure the bike is no where near the quality of even a 500$ bike I consider the bike + all the wrenching experience to have been well worth the overall time.
First test ride out I got 1 second slower than my kom on the climb and 2nd overall on another hill segment and knocked 25 seconds off my previous best.