Thanks for the comments folks, but most of the hard work was done by Frank B.
I agree that using image maps can appear to add more than the cracks and gashes alone, but it really is a matter of tweaking and colouring to acheive what you want. I don't have a problem using image maps where the result justifies it. However, here's one without an image map and the result is still pretty good. I'll post more later.
@Calico if you want the TGD I'll post it later when I get home (not on this pc), but really it's just FrankB's file with adjustments and appropriate maps.
