Congratulations on scoring a great shooter. Under the wear that finish looks original to me, but the stocks are from a couple of decades later; they can't be earlier than 1968 because they have no diamonds around the screw escutcheon. Target stocks could be purchased for K-frames as early as 1950-51, but at the time your gun was shipped it would have worn diamond magnas.
I think that serial number probably points to 1949.
Looks like your gun has the light or narrow-rib barrel. That's the original postwar configuration. Starting sometime in 1949 you could choose one with a slightly heavier barrel, and by later in the 1950s the heavy barrel design became standard.