Oh WOW!!!
In James Hanson's Encyclopedia of Trade Goods-Firearms, he shows a gun with what seems, from what i can see, to have very similar hardware. It was owned by a furtrader-silversmith named John Kinzie but was restocked in the era, according to Hanson, so it doesn't have the original "french" style stock.
I sure hope someone here can get it ,if available, and am looking forward to seeing what can be found out about it.