In my opinion, the gun appears to be a Post-War gun in a Pre-War box. Black boxes were used briefly Post-War, but usually just for "transitional" guns, which this one does not appear to be. Does the serial number on the bottom of the box match the gun's serial number? What is the serial number range of the gun?
In my opinion, the stocks are not original to this gun. Colt did not make smooth stocks like those pictured, except for the Model 1892 et seq military revolvers of the late 1800s. The left escutcheon appears to be the Colt style, but the right one does not. (I am not sure what the right escutcheon on a Model 1892 looks like without checking, so I am not sure that the right escutcheon is non-Colt.)
Colt did not use plain stocks on anything to "keep the cost down for the common man." Stocks were machine-checkered for most of the twentieth century, so the cost of checkering was not an issue. No "modern" Colt used plain, un-checkered stocks, except for the early automatics and military revolvers.
(Apologies to anyone offended by my "delivery.")