I have a D.M. Lefever crossbolt, unmarked as to grade but probably a 7D grade going by the engraving and other features, that has SD&G (Shoverling Daly and Gales) stamped on the bottom of its' Damascus barrels. Also have seen the Lindner made sidecockers produced under the Lefever patent. J.A. Prechtel of Cleveland, Ohio also apparently built guns on Lefever designs.