A magnet should help with the triggerguard material question.
The buttplate and patchbox do not appear consistent with the triggerguard and breechplug finial, and my first thought was a restock, but I could easily be wrong. My impression is the acorn is a recurring theme in western Virginia/West Virginia rifles, so there may be some connection. But these are wild speculations. I'd like to see a more knowledgeable response.
Larry Luck