Thanks again, showing my newbness!
I have a Chorus double crankset from 1991 so I've learned that it will have the pre-ISO Campagnolo taper which is a bit like JIS (but not quite) .
Would a new Centaur 111mm BB fit? because it states on the Centaur spec:
"Also fits 1993 and later Athena and pre-1995 Record and Chorus cranks."
But surely this is an ISO fit?
I know the ISO/JIS situation is debated ad-infinitum which makes it all the more confusing! Sorry for bringing it up again!
After reading all the opinions it looks as if crossmatching the taper standards actually works but can effect your chainline either way by Xmm. Maybe this isn't too much to worry about on a double or triple crankset?