The camshaft is one of the most severely loaded parts of an engine - a fair loading without copious oil supply combined with the sliding motion of the follower over the cam. Years ago I used to do a fair bit of rebuilding of a popular Ford 6cyl diesel. Their camshafts were fine - but often destroyed by Ford's crappy cam followers. The latter were 'chilled' cast iron, but often contained a multitude of tiny blow holes in the casting. Whilst one might think they would hold oil, in fact they damaged the cam.
In your case Stu, in my view that cam is beyond use for similar reasons. Could be reground and hardened again, but surely a good second hand one would be cheaper? Which cam is it?
