Someone posted some XCR parts on here a while back that they had coated in NiB, you might try doing some searches.
Or, you can always try going the DIY route. You can get everything you need for $200 - $300 if I remember correctly. I think I'd try it on some less expensive items first.
I'd be careful about the parts that you coated as the change in tolerance can apparently be somewhat unpredictable.