Campagnolo ergo shifters on older bike

Campagnolo 8-speed cassettes used a slightly different spline pattern from the current pattern used for 9-and 10-speed systems.

8-speed Campagnolo cassettes will not fit on newer "9-speed" and "10-speed" hubs.
9- and 10-speed Campagnolo cassetts will not fit on 8-speed hubs. It is theoretically possible to upgrade Campagnolo 8-speed hubs with newer cassette bodies, but in practice the parts don't generally seem to be available.

In theory you just change the hub body. In practice finding parts, may prohibit this. I would have thought a replacement rear hub, would cost much the same as this magical 8-9 speed hub bodie. Should it be as rare as it sounds.

Good luck!