Rich, sorry to be late. I have a few guns with Whitworth Fluid steel , or similar, engraved one the breech. Each has on the underside of the barrels, in front of the flats "Trade, then the sheaf of wheat, Mark" These guns come from Baker Gun and Forging Co., Lefever Arms Co., and Syracuse Arms Co. I have a nagging feeling that I have another American company gun marked that way, but cannot remember at the moment. Oh, yes, it is an L.C. Smith marked the same way.

http://www.bakercollectors.com/