I think this is a terrific site and I frequently visit just to see if there are any new posts. There is a wealth of information here provided by some very knowledgeable “Detonics Guys” who, while they don't always agree, offer some great insight. I am certainly no expert and make no claim as such.

Here's my question:

I have owned several Combat Masters over the years, all Mark VI's as I recall, and none of them had Combat Master inscribed anywhere on the slide. One of them, my first, did have "Professional" or "Professional Model", additionally inscribed, but (besides "MVI"), that was it. Because this post piqued my curiosity, I also checked various guns listed for sale, along with this very site, and was still unable to locate the "Combat Master" inscription. Were all these guns returned for repair? Incidentally, the only other difference that I can recall between the three guns is that the barrel on the first wasn't crowned whereas the barrels on the other two were. Do you have a photo showing the "Combat Master" markings? I have attached a photo of my current gun.
Be well, Shaun