If it is a flint gun, and original, you probably need a hands on inspection by an expert, or at least some really good photos. Value depends alot on age, maker, condition, configuration, etc. as non military flintlocks were basically custom items made one at a time. So there is no "blue book of values" to consult on that type of gun. Since you are in Indiana, you might be close to the National Muzzleloading Rifle Assoc. in Friendship, down in the SE corner of the state. They have some experts there that know about these things alot. If you take it to a local gunshop, they are gonna try to get it from you dirt cheap in alot of cases. And they probably don't have anyone who knows alot about those type of rifles perhaps. Just modern stuff. So don't be in a rush till you can get some good advice.