Its not a reproduction gun.
Not even a Harper's Ferry, they are all military and very well marked.
I believe this may be made in Ohio or maybe even Missouri. The Stock is unique for a flint-er. So I would say this gun is built from flintlock parts with a conversion cap lock. The bad fit of the drum and nipple to the hammer, maybe bad gun smithing, or over time, the drum may have been removed and tightened down to much. very easy to do with this old iron. The lock may be a Goulcher, he clipped the back of some conversions, and some locks were made this way. The shape of the stock familiar to me. I have seen this style on guns made for over the log shooting maches. The lock screwplate looks almost like "Vincent" (maker) but the work is not up to his standard.
You could send and inquiry to Harry Hunter, C/O Muzzle Blasts P.O. box 67, Friendship, Indiana.
47021 Att. Sighting In. Clear photos are a must, and a description of all visible markings.
Has a nice piece of wood tho.