I've passed it up because I wasn't really interested in stamped wrenches, but this week I finally felt sorry for it and bought it. I knew that the diamond-M identified it as a product of the Frank Mossberg Company. What I didn't realize until now is that it was from a motorcycle kit produced by the company in 1917! Score!
Then I discovered I already had another of the set hanging on the door to my shop with my other oddball wrenches! So now I have both the B and D of the motorcycle kit! All I need now to complete the set is two more wrenches and a 1917 American-made motorcycle.
In 1899 Frank Mossberg and other investors founded the Frank Mossberg Company to manufacture tools, with the intended production of pipe wrenches, bicycle wrenches, and related items. The company was initially located in Providence, Rhode Island and operated independently of Mossberg's earlier business(es), but by 1900 the company had moved to Attleboro, Massachusetts and then in 1901 the earlier business operations were merged into the Frank Mossberg Company. By the early 1900s the company was producing bicycle wrenches in a number of styles, with names such as Sterling and Diamond. In 1927, the company merged with APCO (the Auto Parts Company) to become APCO-Mossberg, and later specialized in the manufacture of torque wrenches.