To my eye, the gun has aspects of the Angstadts, especially Gideon who used the decorative, denticulated, brass panels by the toe plate, left side. The inlays have a flavor of the Upper Susquehanna schools. Nice rifle and it is always a pleasure to see a well decorated rifle in such good condition. It sounds like Richwein may have made the barrel though that is by no means necessarily the case. He may have made the whole gun. Thank you for bringing in here to show around. If you can, take a photo of the barrel marking(s) and let us see what they are. Would appreciate it.
Dick