The most common assumption is that this rifle was made by John Shell and his apprentice, Amos Early, who as noted above, also became John Shell’s son-in law. However, a case can be made that this rifle was made earlier by John Shell and Amos’ father Jacob Earley.
First: The rifle’s #157. John Shell numbered most of his rifles. The ALR Bruce Miller Virtual Museum has nine John Shell rifles ranging from #57 to #422. Rifle #65 is believed to be Shell’s personal rifle, carried by him in the War of 1812 (he served in 1814). Some of Shell’s later rifles were also dated. Based on an analysis of John Shell’s production over his long gunsmithing career, #157 was likely made in the late 1820’s to early 1830’s. Amos Early wasn’t born until 1832, per his tombstone, so assuming this analysis is reasonably accurate (a big assumption!) it isn't likely he helped with #157.
However, Amos Early’s father Jacob Earley was a business partner of John Shell’s in several endeavors in Shellsville, PA, which was laid out by John Shell in 1821. Jacob Earley was also a gunsmith, so collaborating on rifles would not be unexpected.
Second: Earley vs. Early Rifle #157 is engraved “Shell & Earley”. In most historical records Jacob’s last name is spelled “Earley”. However, Amos’ last name is almost always spelled “Early”. Plus, his tombstone in Shell’s Church Cemetery is spelled “Early” and a rifle he made that I’ve viewed is inscribed “Amos Early”. So, while not absolutely definitive, this would also seem to point to Jacob Earley as the likely co-maker of #157.
Chris – John Shell’s rifles can be found here:
http://americanlongrifles.org/forum/index.php?board=43.0