My first CCW was a satin nickel MK IV series 80 Combat Commander in .45 ACP way back in 1987.
Loved that gun but moved to a nickel Model 59 for the higher magazine capacity.

IMO the Commander length is the best version but didnt it come about with aluminum frame in 9mm to compete in the Army pistol trials of 1954 ?
IIRC its competitor was the Pre Model 39.