The faces aren't diamond cut its just round the outside edge of the rim.
hmm i have some that came with the car i think, will give it a go, just dont want to make it worse but tbh what have i got to lose. Do you know if wheel places do like a touch up for diamond cuts or is it simply a full on £80 whack whatever they do?
As suggested, I'd try polishing them first. Hard to tell but if they are smooth when you run your fingernail across them, then it suggests that it may just be the laquer coat that's damaged. Have you got a DA and small polishing pads? If so make sure you masking tape up any vulnerable edges. Failing that polish by hand. Worth a try Unfortunately it's a commom complaint. I've given up with mine and just suffer the scratches, kerb marks which require a full refurb