Hi KL,
Everyone, German, British, Russia, Spain, Belgium, Italy, etc were influenced by French designs. It is less a difference in motifs rather a difference in exuberance of decoration. The Brits were a bit restrained, the Italians simply could not help themselves and heaped on gobs of French-inspired decorations. The Germans, particularly under Frederick the Great were infatuated with French art, style, language, and literature, but not French politics. I think German guns had classic French rococo designs, maybe more frequent use of hunting scenes (often with boars), and possibly a little soft porn. I believe, that would be about right. Certainly, Wolff's book would be a great asset.
dave