Alistair,

 When I took apart my old engine, the only part that looked REALLY bad was the
 camshaft. Besides the cam bearings, that is, but they were the wrong parts
 and that's another story.

 Do you have the book "How to Rebuild Your Air-Cooled VW Engine"? It has
 several photos of worn type IV cams and some text on the same topic.
 Fortunatly, reground cams and lifters are not expensive, it's too bad
 that the cases have to be split to change the cam.

 Dave