My first M1 Carbine

[painter777]

Could the slingwell markings be.......

TRIMBLE
TN
?
BTW, Is the stock a Hi-wood?

Here's a poor picture of a Trimble TN made stock, but was made for a Saginaw, so pay no attention to the lower markings.

Look for Crud under the locking lip of the Recoil Plate. Your picture looks as though the Plate has shifted toward the right, muzzle pointed away.
It very well could be a worn down or issue with the plates wood seat as 1stFlabn mentioned

HTH,
Charlie-painter777
Williamston, MI