Post a pic of the gas block. Also, is the firing pin the early spring loaded type or the later free floating style?
If a 90 or 45 degree sloped gas block and a spring loaded firing pin then it would most likely be a 1950 or 1951 CKC. Otherwise, if a waterslide style gas block and free float firing pin, then a later model CKC.
Data I look at shows it should be an early Russian CKC.