The correct new-tech bargain-basement part for your campagnolo nuovo record (i'm guessing) crankset would be :
post-1-1-1977, 114.5mm 3mm rhs offset-spindle, add 3 mm, buy 118 mm symmetric BB. pre-1-1-1977, 112mm 3mm rhs offset-spindle, add 3 mm, buy 115 mm symmetric BB.
there is nothing magic about these vintage spindles with 3 mm of offset on the right-hand (drive) side. To replace them with a modern BB until you get the correct one, just add 3 mm to the left side, and buy THAT size in a symmetric spindle. The bike industry does an astonishing job of keeping old parts on the road, if you buy an old-fashioned part that was once popular.
Even for 1950's bikes with Chater-Lea oversized bottom brackets, you can buy the Phil Wood cartridge lock-rings and use a Phil Wood or Shimano UN-71/72 cartridge bottom bracket (maybe Tange/IRD, too, with some filing on the Phil lockring.)
- Don Gillies
San Diego, CA, USA