I don't know if you have ever been to the Lewisburg show or not. For me, what really makes that show(and any other for that matter) is the all the originals on display. Mostly upper susquehanna. Most people don't realize the history that PA has with the long rifle.
I'm in the process of building a Snyder County. Had the great fortune to handle an original and get various measurements.
The top one is the oldest. A turkish or Baltic rifle with a Miquelet lock. Somewhere about 1700. A picture of the lock is posted in the traditional thread.
The second is an early style stocked gun that was cut down to a half stock. The barrel on it starts octagon and then goes to round and is about 60 caliber smooth and the barrel is only about 30 inches. It probably went through several reincarnations during it's life. As I recall the underside of the barrel is marked Remington. Remington started out making muzzleloader barrels around 1810.
The third is from a later period full stock gun. The barrel is about 34 inches and is about 40 cal with 7 grooves. I have found no markings on it and guestimate it is from about 1820
The Fourth is a peculiar type of rifle known as a "zimmerstutzen" It was made by Wurfflein in Philadelphis about 1850. It has DST's and a box lock hammer, that strikes a firing pin that is about 24 inches long. the rifled part of the barrel is only 6 inches long about 30 caliber. About 7 inches from the muzzle, on the under side of the barrel shell is a little widow where the shooter can put a percussion cap on a nipple. It is a rather peculiar shape for a butt plate.
The sixth butt is from an 1866-7 Remington Rolling Block in 58 Berdan caliber. A way for Remington to convert some of the left over civil war muskets to centerfire. About 1100 made.
The next on the list is a 40 Caliber Tyrolean off hand rifle. There is no half cock, never was. It was made to be cocked and fired at the line, not carried around.) This style was made throughout the Alps from France Switzerland, Italy and Austria for Schuetzen competitions. Schuetzen competitions were hosted by shooting clubs and were accompanied with much fanfare. Shooters and spectators would march out to the range in a parade and each competitor took one shot at 200 meters at a round target they had decorated. The shooter that hit closest to center was proclaimed the Schuetzen Koenig (King) and then they had a parade back to town where they had a big eating and drinking celebration. Dixie Gun works sells a modern variation of this gun. They call their version the Waadtlander.
The last is a Martini action made for interchangeable barrels made by Emil Pachmayr, the barrels would have been in an 8 mm centerfire offhand cartridge and the barrel on it is a zimmerstutzen barrel. The 6 inch insert is missing from the end of the barrel. Emil Pachmayr was the European 200 meter offhand champion back in the 1910 to 1915 era. That butt stock is almost 6 inches wide. The huge cheek piece cradles the face perfectly into position to look down the sights. Unfortunately, I do not have the sights either.
Somebody complained in another thread about the crescent butt on the Lyman GPR, I figured I would post some butt plates through the ages.