I built up a NOS late 90s steel frame with a similar era Campagnolo Chorus 9 speed groupset. Has gone well, except the stays/dropouts don't seem to quite like a 9 speed cassette. The second smallest cog (14T) rubs a tiny bit and the smallest cog (13T) rubs a lot, so as to be unusable. I've set my limitscrew to keep me off the smallest cog and have done lots of km that way, but I'd really like to use the smallest cog and am trying to work out how. I tried swapping the hub spacers, but on this particular hub, that would have moved the dish way too far to the side. So basically I'm trying to figure out the cleanest hack (bonus if it's cheap as well) to get the full cassette usable on this frame.
I've attached a picture for clarity.
Oh also, OLN of the hub (a fulcrum racing 7) is 130 and it fits without trouble, but given the age, it's possible it was originally a 126, though I think the paint job is original so perhaps not (I took off the paint around the dropouts, when I, er, discovered this problem).