Ken, attached is a picture showing the barrel lugs on my Birmingham "Trade Gun".
My shotgun was made by JP Clabrough & Johnstone. I believe it was likely made for the Canadian market through the Hudson Bay Company, which was the biggest retailer in the country at the time. In the book 'Trade Guns of the Hudson Bay Company 1670-1970' by S. James Gooding, the first mention of the English breech loading shotgun is listed in the first HBC catalog dated 1896-1901, these English shotguns were simply listed as "The Imperial Line", three models of these shotguns were available for purchase. The book states that, “the HBC played heavily on brand recognition, a sales technique which began on their firearms with the short-lived Garry model announced in 1896. Some, like the Imperials, were made in great quantities to special order for the Company while others were probably taken from the manufacturer’s inventory and stamped with a brand name.” The book goes on to state that, "most of the muzzle and breech loading shotguns in this period were made by the traditional London & Birmingham suppliers: Hollis, Bentley & Playfair, C.O. Bircham, C.G Bonehill (Ltd.), W.J Jeffrey & Co., T. Bland & Sons, JP Clabrough, and later JP Clabrough & Johnstone (HBC production between 1894-1920+), Joseph Bourne & Son, and Bentley & Playfair." pgs. 102-105, 147. There is an old HBC Advertisement of the Clabrough & Johnstone “English Hammerless Shotgun” “Used by Fur Traders All Over the Dominion” on pg. 105, fig.119, and is named “The Bay Gun” looks identical to my shotgun, although my shotgun doesn’t bear any retailer branding. Fig. 119 states, “This advertisement illustrating a double hammerless gun made in England by Claborough & Johnstone, probably appeared in the 1920s. No examples of “The Bay” have been reported.”
Anyway, I think the trade guns are interesting, a tangible piece of history.
Tim