I’ve always liked fine blued firearms. Even though my corrosive sweat destroys them when I’m within six feet of one. 🙂
Had a friend years ago who picked up a Colt LW Commander for $125 (This was the 70’s). The slide was in bad need of refinishing. He spent hours with steel wool and degreaser, followed by a cheap cold blue. (Birchwood Casey?) Never got it to look right, and later traded it for an early S&W model 60. (Which I later acquired 🙂 then had stolen 😦 )
I spent years touching up my various blued firearm and parts with cold bluing and bluing pens (and scratches on alloy frames with oxide pens!) Never seemed able to get bluing solution of a quality formula (this was pre-Internet). I did hear there was one Canadian formula, though. It was like the Holy Grail of bluing!
Years later, a gunnie friend was helping a neighbor with her recently-deceased husband’s firearms. He’d a 50’s vintage Colt Python that had developed some rust issues in storage. We cleaned her up and applied a good cold blue. It was like color-changing steel magic! Colt metallurgy was excellent! (Of course, it probably ruined the value the unadulterated gun would have received.)
My own NM 1911 (The Bob Hall Signature Model) had a blued slide that had been dinged-up and developed some rust and pitting. The frame was a stainless Vega – no issues there. I tried cold bluing a number of times, but was never happy with the result. Eventually, I coughed up significant funds ($200, in 1983?) and had Robbie Barkman work his magic, coating the whole gun in Poly-T and putting NP3 on the internals and mechanicals.
She looks worn on the edges today, but still runs 20K+ rounds later. All I do is change out the recoil spring every 3K rounds, or so, and keep her lubed with lithium grease.
And nary a rust issue to be seen! 🙂