Your picture showing the rear sight;
I don't see any punch type (crater) stake marks to tighten your sight to the dovetails of the receiver.
Can see the 1 chisel type stake mark on the frt right side.
Even though the metal that was in that stock has been thru a aresenal rebuild...
Was it your current carbine metal?
I can see upgrades, but could these have been in the field?
Any way.... Look closer under all 4 corners of your rear sight, note the style staking or lack of and let us know.
OK?
Ch-P777
P.S. Had a nephews Grad Party today in Northville.