Campagnolo bottom brackets went through a number of changes, 1960s through 70s. The introduction of the Nuovo Record bottom bracket, with its thick, rifled cups required a spindle with the bearing races significantly closer together than the Record and Gran Sport bottom brackets. The Super Record bottom bracket, with a titanium spindle, used smaller (3/16" vs 1/4") balls, so its cups and spindle do not interchange with Record or Nuovo Record. Super Record crank arms, OTOH, are the same as Record and Nuovo Record, and will mount on either bottom bracket. CPSC-required changes in the late 70s meant the drive side crank arm needed more offset to clear the CPSC-compliant "lipped" front derailleur and a correspondingly longer spindle. All in all, a "hot mess." Campagnolo USA published this article to explain things:
https://drive.google.com/file/d/1TZw...usp=drive_link