Wanted: Campagnolo 8 speed adapter for 9/10 speed (KIT-03)

The width of all Campy bodies is the same. The difference is the thickness of the spacers, 8-speed is thicker (colour black).
Solution: buy a 9-speed cassette, throw away the larger cog, fit the remaining cogs with the black 8-speed spacers to your 9-or 10-speed wheel.

This doesn't work. Because the width of all the freehub bodies are the same, 9 speed cogs are thinner, not just the spacers, so that they fit on. I tried it. As you shift up or down It becomes slightly more and more out. I think you can buy special spacers so that you can use a 9 speed cassette, drop a cog, and have an 8 speed one. Simply using a 9 speed cassette with campag 8 speed spacers doesn't work though.