At the Vintagers(2009) I did happen to see a Heinrich Scherping Hannover double totally made by Sauer as a Facile Princeps(
http://books.google.com/books?id=aMECAAA...gun&f=false ) with patent numbers 10343, 23490, 505006 which I think went with the countries: Germany, ?, & America. Thanks to Steven Meyer for shedding the light on what the patent was for. It did however still have the typical Rigby style forend latch as seen on the majority of Heinrich Scherping guns. I think this goes a long way toward Heinrich Scherping sourcing Sauer for his longarms with the possiblity of a few other Suhl makers.
Kind Regards,
Raimey
rse