I finally got around to requesting Cody research and yesterday received info that the original order sheet for this Model 21 isn't available but there’s a Repair Order dated late December 1944. Besides some other small work, it covered fitting an extra set of 16 gauge/28" barrels, Right Improved Modified and Left Full. Finished in mid-March 1945. That delay was no doubt due to war work. Interesting that the Right barrel breech is understamped Mod instead of Imp Mod. One of these days I'll get around to patterning her to compare bare shot with modern shotcup loads.
Old timers told me when I was a kid that shotgun shells were severely rationed during the War and I wonder why the owner gent got the second barrel set fitted right then? As said many times, if these old guns could talk.….
Ringneck load of my youth …..