I didn't see anything that would convince me that this gun could only have been made in Ohio. And, with no initials, no names, no dates, you are asking a lot more than can be realistically expected. Of course, there is always some crook out there, who will put a big price tag on nothing, and claim it is something, when he knows there is no evidence to prove him right or wrong.
My brother bought a gun years ago for #75.00 that was pretty much junk. It was an old barrel- we now know from various markings and examination that it dates back to the first decade of the 19th century at the latest, but could be 20-30 years older than that--- that had been on a long rifle, with barrel keys, suggesting a flintlock, used with a hand made bolster and shotgun lock to make a percussion LH half-stock rifle. The hammer was broken. The escutcheons were torn out with huge chunks of wood missing there and around the lockplate. The trigger guards is a parts piece, as is the buttplate. There is a single initial on the buttplate, but all his efforts and mine to find anyone who could tell us anything definitive about it failed miserably. He has since had the barrel rebored, to a larger caliber to get rid of deep pits in the bore, and had the stock repaired by fitting new pieces of wood, where original wood was missing. After he shot it a number of years, the breech area began to fail, and it has since been rebuilt, but not to his satisfaction. He is comtimplating replacing the entire patent breech with one made from new steel. The barrel remains the original piece that it was, except it is now a .42 caliber rifle. He has shot the rifle at the Sgt.York Chunk Gun Matches in Tennessee a couple of times, altho he is planning to use a new rifle this next March while he fixes this old gun once and for all. At best, he figures the LH percussion gun was built in the 1860-70's , based on the style and age of the lock. Its a classic " hardware store " shotgun lock, sold to replace worn out locks on DB shotguns. The stock looks like it was cut from a plank, as both sides are flat, and parallel to each other.
It would be fun to know its origins, who made the Percussion gun, where the flintlock barrel came from, and what kind of gun had it been on, etc. but that is not how guns were used " Up " in the days. Nothing was wasted, and worn out or rusted guns were repaired and used until they could not find parts, or someone who knew how to repair them anymore within a reasonable distance from home. Many percussion guns stopped being used when local stores stopped stocking percussion caps.
Mike, I know you were not criticizing his workmanship, and that you just wished that the restoration had left the original finish on it. Pictures don't show us everthing, of course, but from what I saw, and his description, I would be the first person standing in line to see how a experienced restorer solved those problems, at a cost that could be justified by the gun's value.