Dave B.:
I usually stay out of these discussions as someone always chimes in that my response was "wrong" and just plain "stupid", but anyway, I think the gun was from the Bedford or Somerset area of PA or maybe even Fulton or Huntingdon Counties. As far as the set trigger adjustment screw, I personally have not seen such an arrangement but assuming gunmakers in these areas made their own locks and set triggers long after other makers began purchasing them, the arrangment seems plausible. Is this a single set or a double set type of set trigger?
Anyway tis a beautiful gun. I thought I recognized the eagle on the cheekpiece as Whisker and Yantz (2001) depicted a number of stylized eagles in their book describing the makers in these counties. However, review of their text found no similar eagles. As popuular as these guns are, I'm surprised no one has chimed in already with a response.
Jim