At your suggestion I did revisit the 2018 DGJ and read Seyfried's account of his 14 gauge duck hunt; his was a Lancaster single shot hammer gun that he found very effective (4 for 4 on Mallards) loaded with RST 16 gauge shells wrapped in a layer of duct tape to keep them tight in the chamber. I've accumulated 6-8 original 14 gauge paper shells, 3-4 NOS paper cases, and 5 Greener 14-bore brass cases modified to fit the chamber (bases on standard cases too thick, won't allow gun to close). Obviously I don't want to shoot the vintage paper shells, and with only a limited number of brass cases it seems using 16 gauge shells is the way to go. The gun I have is a hammerless Damascus double gun labeled JN Scotts; and the best information I can find is that the JN Scott gun was made by WC Scott and the name JN Scotts was assigned to guns for export to the US (and maybe elsewhere?). This is a true sidelock and a quality piece inside and out. There seem to be a fair number of JN Scott labeled hammer guns noted on the web, but I'm only aware of three hammerless examples thus far; a 10, a 12, and my 14 bore. These odd bore guns are one of the factors making shot gunning interesting and fun.
