SKB has used just about every imaginable finish, AFAIK, including black chrome, blue, brushed stainless (receiver only), and electroless nickel.
Personally, I put a blued receiver at the bottom of the list. It looks like crap after a little real-world use. Old Brownings are some of the worst. I've seen too many of them that
would be in 98% condition, but the worn-off blue makes them look like they're trashed. The coveted long-tang trigger guard (which my old Ithaca SKB has, also) is the first thing to look bad.
CCH would be as bad, or worse, but per an earlier thread and some looking around I've done since, CCH is often coated. Bluing isn't. OTOH blue doesn't fade in the sun, CC does.
Guerini coats both its CCH and coin finishes with urethane. That would imply that neither one of them is durable or rust-resistant by itself.
Personally, I'd love to see more stainless steel. The appeal of tradition went away for me when I spent some time bronze brushing a bunch of rust out of the engraving of an O/U's receiver, after I got some sweat on it and missed wiping off a few spots. Electroless nickel is all right, too. I guess urethane over the finish is all right, too, with one problem: I'm not sure how you tell if it's worn through.
I like stainless revolvers, too. Polished blue does look nicer -- as long as you plan to keep the gun in a sack-up in a safe, oil it frequently, and never actually carry it.
Thanks for the info!