Wow, that photo is really striking! Looks like something that came out of Jimmy Hoffa's vault. After recoiling in fright, it looks like a cool old-school snubby when taking the second look. I agree with you as far as stripping off the little bit of nickel that's left. I think I'd go with beadblast parkerized or maybe just try to cold blue it with Oxpho after blasting it. A spray-on finish would be my second choice.