Often gunsmiths that took their training on the cusp of the breechloading/cartridge era found that although they had been trained to build guns that were now getting hard to sell, there were still customers that wanted a muzzleloader because of the economical price of the gun, and its ammunition. A lot of these little known smiths worked a farm for the majority of the year, and built a gun or two in the winter months.
I own a Lehigh smooth rifle that I suspect was made by such a smith. But, alas he didn’t bother to sign it, so there’s no way to be sure.
Hungry Horse