Colt New Service in 44 S&W question on the markings

[Lee Enfield]

Your New Service was built as a .455 in the 1914-16 period.

The barrel is from the end of production (mid 1930's to early 1940's).
It's not factory Bluing.

Many NOS spare parts (barrels and cylinders) were sold off by Colt between the late 1940s and 1960.

Someone (other than the factory) rebuilt that revolver into a .44 in the 1950's to 1970's period.

The British markings are WW1 era, the C^ could be as late as WW2.

The "Russian and / S & W Special" ".44" caliber marking is the one that everyone goes GaGa over...