Originally Posted by bccycleguy
Some wheelsets can handle both Shimano and campy cassettes. Maybe check that first (I'm sure you probably have). The Shimano cassette being a little bit narrower than the Campy uses a thin, little washer to take up the extra space on the inside.
This is news to me as Campy and Shimano use different spline patterns on their cassettes and thus, different hubshells. Please explain.