When I was a little 'un, my mama would take me to the Warren Clinic in Laurel MD, which was two doctor brothers and another doctor. There was always an American Rifleman issue or two in the waiting room. I remember seeing ads for the H&A underhammer rifles. They weren't what Davy and Dan'l carried, but they WERE muzzle loaders. I've never owned one, but I ain't dead yet either.