A buddy's girlfriend needed magazines for her S&W Model 39 (long story, but we couldn't find the 2 mags she remembers) so I went on the hunt for them. Shocker, they're expensive and hard to find. I ended up getting a couple factory 39 mags relatively cheap off of evilbey that the offeror honestly claimed they had some rust. "Some Rust" turned out the be starting pitting. Considering the difficulty of finding these things I decided to try to clean up the half a postage stamp area of pitting. Cleaned, degreased, taped and then I went to work scraping with a flattened brass 308 case, then brass brushing and finally broke out my Work Sharp with the knifemaker kit with the medium fine polishing belt to avoid the sin of putting too much power into moving metal. I got them cleaned up (I took the pitting to "wavey" so I didn't remove any more material than needed) and sprayed clean of all particles with PB Blaster. Some white is now visible, but 90% of the blue is good. I gave them a good dunking in Strike Hold to protect the metal and need to look into the question of protecting the surface permanently. I can get them Ceracoated, but I'm concerned about the fit in the firearm considering the thickness of Ceracoat. I can cold blue them, but that's not exactly the most protective finish. Hot blue may be the best protection with the thinnest surface change between the other two. Am I being too concerned about Ceracoat thickness? I've been told hot blue is a pain and can leave uneven surfaces very easily, but is that your experience doing hot blue? Am I overthinking, almost certainly, getting this done as a favor when the folks I'm helping can't even keep track of the original mags?