IMO, this is not going to be a real valuable gun no matter what you do.
If you are willing to put a lot of work into this project, I do have a suggestion.
Replace the stock with a partially pre-carved stock from Pecatonica River. Stocks from them will have all of the outer surfaces carved but will require the removal of about 1/16 of wood (or a little more) to get it down to the smooth slender shape it should be.
You can buy these stocks with just the barrel channel cut and the ramrod hole drilled. This allows you to install any lock, trigger, butt plate, trigger guard etc, but be forwarned,
the amount of work you will have to do is going to be the same as if you had bought a good american lock and all of the rest of the hardware to make a truly nice, quality gun.
My price list is probably out of date, but it says the stock price would be $43 to pre carve it and cut the barrel channel and the ramrod hole plus the cost of the wood.
If I were doing this, I would buy the cheapest wood he offers, which my book says is the straight Maple with 0 to 30% curl. This would set you back $80 (unless he's raised the price in the last year or two).
Total stock price = about $137 including postage.
If you decide to do this, measure the distance across the flats of the barrel. My old Dixie book says your gun uses a 7/8 inch barrel, but you better check it anyway.
Give him this barrel channel size, tell him which style you want and your in business.
If I were doing this, I think I would shy away from the older style classics where a precussion lock would be totally out of place and the width of the butt would be way too wide for your hardware and ask for a "Tennessee Mountain" (fairly straight comb and lower stock surface) or a "Southern Mountain" style (curved comb and lower stock surface).
IMO, these styles lend themselves to using whatever lock and hardware was available to the gunsmiths in the area so it would be fairly PC for any time after 1830.