I have an old steel road bike with a Campagnolo drivetrain and a 7 speed cassette. I wanted to upgrade the wheels and put those open mavic that have a shimano hub, is it even possible ?
Campag derailleur (1990-2000) and a 7s or 8s Campag shifter will work fine. Campag 7s and 8s cog spacing is identical at 5.0mm.
However the pull per click of Camapg and Shimano shifters (and corresponding mech movement) are different. So don't mix mechs and shifters.