danish jaeger rifle Model 1807/48 with bajonet https://www.lauritz.com/en/auctions/hunt...8071848/6496081

target rifle by morgenroth in gernrode https://auctionet.com/de/3851091-morgen-...ndert-schlosser

coming back to this problem "Quite a fancy piece there Lancaster - would that be the starter under the buttstock? "

here is another one, now a belgian made double gun https://auctionet.com/de/3879048-doppelrohr-schlingengewehr-belgien-um-1850-33

same kind of knob, I know this from target rifles where its used as a hand support for off hand target shooting but on a double gun it could only be some kind of starter.