M1 stock cartouches
There is a relationship between the initials stamped on the wood under the left sight knob, and the serial number range. The cartouche is the acceptance mark of the arsenal's inspector. Some guys had the job for long periods, others shorter.
If the serial number does not match the cartouche, it is not a major showstopper. Many rifles had their factory stocks stripped off at any number of authorized repair depots. Repair were done, or new stocks installed.
The Danish complicated matters by stamping the rifle serial number in frighteningly deep characters on the butt. For a Danish rifle, the two should match up. At least you can know that is how it left Alan Lever's store, and not been rebuilt at any number of unauthorized kitchen table repair pitstops.