You sure about that? I know the history about them pretty well and that is not so,ething I have read before.
my MK1 is the first model they made.
i just read up a bit, and while they used some colt parts initially, the slide, barrel, and frame are Detonics in origin.
read here.
Parts Compatibility
Combat Master parts that are compatible with standard Colt Government Model production:
Extractor, firing pin and spring, magazine catch/spring/lock, slide stop/safety plunger assembly, plunger tube, trigger, mainspring housing, mainspring cap, mainspring housing pin retainer, mainspring cap pin, mainspring housing pin, stock screw/bushing, safety lock, hammer pin, sear pin, slide stop, barrel link/pin, disconnector, sear, hammer, hammer strut pin.
Combat Master parts that are different from similar Government Model parts:
Frame, slide, barrel, rear sight, firing pin stop, “grip plate” (grip safety), sear spring, magazine, stock panels, recoil spring guide, recoil spring cap (plug), recoil springs (two or three, depending on model).
https://www.sightm1911.com/lib/history/detonics.htm
sorry OP, hoping this lends to the knowledge, and thusly, the sale of your pistol.
someone will be lucky to own it.