I recall seeing several other J. Young/ Easton long rifles. I checked my Eastern PA lsit and was amazed to see I have nothing on this man--nothing at all. Even Sellers apparently could not find much of anything to plagiarize. But you are correct, c. 1820 or so, Easton area. Wonderful gun! I trust this will go in the library as it should. Such guns simply point out what Kindig said 50 years ago-- there is lots of work tyet tyo be done by those willing to undertake the research. If it's your, my heartiest congratulations!