Nordnecker,
The original rifle is made from walnut. I would use Chambers late Ketland flint if you can find one (just round the tail) and modify Davis #4 triggers. The original rifle has an iron butt plate, patchbox, thimbles, and trigger guard. It has 40 poured pewter inlays and nose cap. A few of the inlays have gotten loose over the years and someone in the past has put a nail in them to hold them in. If need be, I can send you a rubbing of the patch box. I would make the trigger guard a bit more graceful, and the original triggers are a bit heavy. It has a very nice rear sight that I have copied several times on mountain rifles. I can send you a photo of the rear sight if need be. The finished sight is well worth the work it takes to make one by hand. I think it is a .38 cal, so a .36 or .40 would be close. The original barrel is a straight 15/16 across the flats, and I think it is about 41 inches in length (I haven't measured it in a while, so I could be off a bit). I would use a straight 13/16 44 inch long .40 cal. to get a bit thinner rifle. Just my thoughts.
Roger Sells