Our bike shop's paint guy clear-coated a bare metal Chimo a month or so ago. Apparently the trick to durability and longevity is to use a clear primer, which is not at all widely available and is pretty expensive, like $200/gal. Having seen the bike in question, I'd have to say that it's worth it.
I keep thinking that I might gun-blue one of my frames, and silver-plate the lugs. I think that'd be hawt as hell, but I also think I might need to clear over that to keep it looking nice.