You may be correct, but I can't read the mark either. 1920s would be late for damascus, and again, the orginal mark would be 1 1/8 oz Shot. It looks like the 1 1/8 oz. over-stamped something on the L flat, followed by CHOKE.
My very limited list of WR SNs indicates 1884-1893 1400 - 1500. 1924 starts at 1800