TommyG, this smooth rifle was stocked by Isaac Berlin of Easton, PA - which is just 10 miles east of Bethlehem and C's Spring. There is another rifle by Berlin with similar carving and a side opening brass box like Oerter used, probably was available locally. George states that the original lock was English style converted to percussion, and shows the original lockplate at top of p 369. The other rifle carried a German style lock, also converted to percussion. Quite a few contemporary copies have been stocked of both this smooth rifle and the other rifle. You should be able to find photos in books, articles and KRF photo discs.