I thought some of you might enjoy the background on this rifle that I just learned today:
I went back to the gun shop today and asked them if they could contact the gentleman who had brought in this Andrew Kopp rifle. They were kind enough to call him and I had a very nice conversation with him about the history of this rifle.
Earl is 89 and lives in Johnstown. The rifle has been in his family since he was 9 years old, and the prior owners lived at the Spangler farm in Shanksville PA, near the current Flight 93 Memorial. Earl recalls being told that this rifle was brought to Somerset by the previous owners from Indiana County PA, and that it might have been manufactured around 1860. (Andrew Kopp retired from the trade in 1863.)
Earl always liked to tinker with stuff.
When he was 12, Earl took apart the rifle and tried to remove the breech plug, which was seized.
He couldn't get it apart, so he put the breech end of the barrel in his family's wood stove to heat it up, to see if that would let him free up the seized breech plug.
He didn't know the gun was loaded, and the gun fired off when it heated up. 
Fortunately, no one was injured!
Earl subsequently worked as a machinist for US Steel in Johnstown PA starting in his teen years.
He machined the sealed ignition device in these photos
when he was nineteen, 70 years ago:
He also ground off the surface of the hammer at that time, so it would contact the pin on the sealed ignition device:
He was never able to get the gun working, but the gun has been in his possession ever since, providing an 80 year history of the provenance of this particular Andrew Kopp rifle.
However, he was clearly very fond of this old rifle, and was very pleased that someone had bought it that would treasure it and have it restored.
