Mountainman,
If you live anywhere near Somerset, check out the nice folks at the Somerset Historical Society, just North of town on 985/601. They have several Somerset rifles in their collection along with a Somerset rifling machine. One of their rifles is a Knupp rifle, look here under Antique Gun Collecting - Knupp Rifle. The rifling machine was likely used to rifle the bore of this particular gun, look under Gun Building - Rifle Bench.
As far as a flintlock Somerset County styled gun, I can't help you there. That may be a very scarce item.
Jim