Based on a number of details on your rifle, including the highly pointed butt plate heel, rather thin butt stock, lack of forestock & lower butt molding lines, double-spurred guard, and what appears to be commercial triggers, I think a more appropriate dating of this percussion rifle would be about 1840 or a little later.
You have a very nice family heirloom and are fortunate to have a family who took good care of it and passed it down through the generations with a lot of pride.
Shelby Gallien