As I already wrote above, you should not regard this rifle as an American gun. IMHO it is no more an American gun than a Griffin & Howe on a Mauser action is a German gun. The barrel, stock and engraving were certainly done at the Sauer&Sohn factory in Suhl, Germany, hence the Germanic appearance of the whole rifle. LRF is right: German factory engraving usually is done by several men, f.i. a master doing the overall design, another the animals, a third the scrollwork and a fourth the background stippling. The pistolgrip-cap may be a later addition and may have been done by entirely other engravers.