Same ceramic coating I believe we used. I have a snub Mod 37 airweight that was done with it as well........Used it as an ankle rig backup when I was a deputy and on road trips. No oil or lube meant no dust bunnies or dirt . Good stuff !
After I learned how to apply the stuff [in airframe and powerplant school circa '75-"76, same time as I learned how to Magnaflux] I did that for the Navy in the Crane small arms shop for a while, and did it as an outside contractor for a while afterward. Among other projects, I did George Nonte's Ingram MAC 10 and a .44 AutoMag before he passed away, and any number of allow-framed handguns whose anodizing had worn, including almost a thousand Illinois State Police M39 S&Ws.
And, around that time, there were some local cops who talked to me real nice, and I redid their worn-finish aluminum D-cell Kel-lights and B-lights, in a day before the Mag-light folks were in business yet. Some of those big aluminum flashlights had somehow developed teeth marks on 'em....