Nice looking rifle. It has a number of Kentucky details that include: straight comb and toe lines on butt, butt plate return a normal length where TN returns are often longer, extended square shank coming off percussion side lug, flattened area at bottom of cheekpiece, at times no flange on rear pipe, and long 2-screw tang. The "BlueGrass" lock was probably purchased in Louisville as well...or from a store that purchased its stock from Louisville. The nicely shaped guard for an iron mounted gun, along with good looking triggers, are also found on southeastern KY guns, as are the mixed-metal mounts with larger pieces being forged iron and small pieces sheet brass, as on this rifle.
However, the rifle also has a couple of details that are abnormal for a Kentucky gun: large side facings with lots of wood left in front of and behind lock plate, thick and nailed-on toe plate, and short barrel well under 44". The sharp ridge coming off the back of the cheekpiece and running over to the butt is also seldom seen in KY. If it is from Kentucky, it would be from the southeaster part of the state, in the "hill country" area near Tennessee.
The longer-than-normal comb, which creates a short wrist, is seen on the Alfred Bearden and related rifles of Tennessee, although Bearden-related rifles often have a larger, more pronounced rear spur on the guard and a heavier front post [if brass]. So, after all that, we have another interesting "southern" rifle with somewhat mixed characteristics. If it had a fourth pipe and a 46"+ barrel, I'd favor KY for its home...and it still may be where it was made. But on this particular rifle, I'd probably lean a little more toward TN, in large part due to the long comb line. And I'll always wonder if, by chance, the barrel was originally longer and neatly shortened by a good gunsmith...in part because the rear sight sits well behind the rear pipe, rather than at the rear pipe as in KY, or a little beyond the rear pipe as often seen in TN. Shelby Gallien