Loving the magnificient Swiss bikes of the 60s as I do, I have both a Swiss thread Campagnolo BB set and a Stronglight Swiss thread BB set. The Campy appears to have the standard embossed lettering on the fixed cup, 35X1, but overstamped with a "G". The Stronglight cups have no markings whatsoever on either side, inside or out.
Bill Curtis
Costa Mesa, CA