I have a bunch of progress shots of mine so far which I'll post soon.
I used a dremel to remove the built in resin pearls and stones to replace them with 'real' ones, added the blue marble (textured vinyl covered card cover from a notebook) and white pearl inlays (guitar pick guard), and also the thin borders between them using strips of styrene.
The cross is now ready for gold vacuum metalising. Once that's done I'll glue the marble and pearl inlays in.