Uhmm...... I just bought shifter cables for my 1st gen Campy Chorus shift levers...... Guess what,....... the cable heads do not fit in them. Got another set of new cables in my stash I bought not too long ago.......same problem....
I think the mid to late 80's Campy shifters (C Record era) had the same size cable head wells as the Simplex Retrofrictions.
I'm planning of using my Dremel at slower speeds with an abrasive drum tip and roll the heads against it to reduce the head diameters....very carefully....