I can tell you from experience that current model Campy Record Pista crankset and its matching bottom bracket are asymmetrical, and while Italian threading may be same on both sides, as you can barely see in TejanoTrackie’s pic & in plain sight here, it is so well marked that you would have to be a moron to put one in backwards:
But getting back to OP's problem...you did right, one would ordinarily expect the crank and bb you picked to work well with your frame. However, when putting Record Pista cranks/bb on my mid 90s Supercorsa Pista, I found that there was just barely enough room between the chainstays and crankarms on both sides for things to work. And the stays on my bike are almost…dainty. I used to think it was great to have such tight clearance on my bike til I foolishly tried to fit a cadence counter in there.
Besides offering my small bit of experience with the same cranks and bb that you tried, I don't have much helpful advice other than maybe this is a case similar to the ones where Omnumnums wouldn't work on certain frames. And that if you don't want to consider a different crankset, then unfortunately you may have little choice other than trying a bottom bracket with a longer spindle. For instance Campag Veloce, or there is 115mm Miche, or maybe even something really vintage like Chorus/Nuovo Record?
Anyway, I am looking forward to seeing if this "mystery" gets solved - Good Luck…