Thanks for replies, I suppose its a case of is the corrosion going to damage the seals or new seals on a refurb. Re chroming doesn't seem worth it I like the idea of varnishing and could perhaps see that working.
thanks mate - will give that a go.Remove any rust lumps and fill pits with epoxy resin,run seal over ball to smooth out before resin sets.Use the 5 min stuff, lasted a couple of years on my old series 2.