I have extra sets of Campy races and cones that I can use on campy hubs dating back forever. That's one of the advantages of Campagnolo.
No such luck with old British hubs. So when I get one that "indexes" I take out some carborundum, some old ball bearings, and an old axle with cones. I cover the race in carborundum, load the bearings, and install an old axle with cones and nuts. Then I spin the axle with an electric drill. After 10 to 20 minutes I dissasemble and clean. If needed I try again.
Hardware store carborundum or grinding compound comes in a rough/fine tin. Carborundum will smooth out any and all pitting with a bit of determination.
Unfortunately, I can't speak for the longevity of the results. I guess it depends on whether the races (or bearing surface) were hardened throughout or just on the surface. But I can speak for the finish: better than new!
Amir Avitzur
Ramat-Gan, Israel