We need to see a bit more of the gun before we can get a real feel for it. One detail that hurts any analysis of a longrifle is the apparent loss of its original guard. Two sets of pin holes can be seen, indicating an earlier guard was on the gun at one time with different positions of front/rear mounting tabs.
I like the horse head, which is better shaped than some I've seen. The side facings with their slanted front ends should help. I do not see the "moldings" you mentioned, and can't see any molding lines on this gun. The shape and length of the tang, when available, should also help a bit. If I was making a WAG right now, I'd lean toward the Carolinas.
Shelby Gallien