That's very unusual for an L.C. Smith 12 ga to have a 2 3/4" Chamber stamp, they were always 2 3/4"
This period gun was assmebled after the floor collapse, and Marlin decided to close the operation in Fulton and move everything to New Haven, Ct. They lost key personnel in the move and it's quite possible "newer employees" not familiar with the practice stamped some barrels.
I have a circa 1946 Field Grade FW S1825 that doesn't have any stampings on the top of the barrels, but on the watertables has the serial number, Field and Hunter Arms proof mark.
To me this is what makes collecting and researching these guns interesting.
