I believe the correct term for this style of rifle is a Schuetzen. My understanding is the countries which were interested in shooting these types of rifles were Germany, Switzerland (large German population) and America (early on a large German population). This one is set up in a more military format which wasn't uncommon back in the day as you might be expected to take your rifle with you to war. Figuring out the caliber might be able to allow you to narrow it down better as certain countries would be more likely to use certain calibers (I believe the Swiss
preferred .43 caliber but don't take my word for it, this isn't my area of expertise).
Some pictures of the front and back of the rear sight might also help a bit.
Hopefully that might give you a good area to start searching if someone doesn't already know on here and show up.