Earl Lanning asked that once. I've only seen one, back in the mid-90's. It was a musket, made in the US, styled after a Bess and the barrel had Dutch hallmarks. It was for sale in Long Island, NY together with a riflemans knife and a beautiful War of 1812 Commission for a NY Company. The claim was that they were found together in the wall of an old home, on the north shore, during renovations.