I picked up a 1973 (guess) Raleigh Carlton Competition frame. Sweet old-school 531 ride but I never fully trusted it. (The stop for the DT shifter clamp wasn't fully brazed.) I had several other details I wanted changed also so I took it to my framebuilder asking that it be stripped, then appraised. His appraisal? Almost all the lugwork needed braze flowed in; that some were little more than tacked. "The paint was holding the bike together." There was cracking in several tubes, almost certainly due to the lack of support from the lugs. He spent 4 hours brazing the lugs for their first time.
There was one plus. No heat distortion. That 40 yo frame was spot on true.
Ben