My late Uncle Gustav bought a 20 Gauge Trap Grade in 1937- 28" ventilated rib barrels, beavertail, pg, AAA select wood with leather covered pad and of course the SST and AE. I have owned it since he passed in 1976. Very little blue and wood finish wear-- just about a year before Don Criswell, the California dealer who specialized in M21's- he offered me $13,500 for it with the factory trunk case and paperwork. I passed. Pre-WW2 small gauge ORIGINAL M21'S are way more desirable, as better wood and workmanship was evident then as found on the post 1946 production guns. Even Jack O'Connor said so. Your gun might well fetch $12K- and the forearm on mineis a solid as they day it left the factory.