The Campagnolo Velox was a shinier version of the Valentino which existed only so the manufacturer could say the bike had Campagnolo! They're not very good. A Gran Sport, Nuovo Record, Nouvo Gran Record or such would be a nice replacement, or a Suntour Cyclone if you don't feel the need to keep it all European.

The front is probably the boxy Valentino, not much reason to keep that either, match to what you find for the rear.

Typically all friction stuff is pretty interchangeable.