As a follow up from my previous question I decided to change my Campag Veloce 53T chainring. I bought a BBB 50T chainring. I tried to fit it over the weekend but it wouldn't fit.
I think the problem is that the original chainring is about 3mm thick where it bolts to the crank arm and the BBB one is 4.5mm. Below is a photo showing the gap where the chainring will not sit flush against the mounting points, and a diagram attempting to explain where the problem is.
I've had a look at Campy tech docs and can't find anywhere specifying the width of the chainrings at that point. I assume the BBB one just isn't compatible. Or have I missed something?