Joel, I've always liked that rifle, particularly the engraving.
Rob, you can see more of #323 in the ALR Museum. The edge of the buttplate is very typical of John Shell's work. Dating his rifles is a challenge. While he numbered his rifles, he only dated his very late rifles. See #422 in the ALR Museum dated 1869. Dating estimates are further complicated by the fact that John Shell was an active gunsmith form his early years (21 years old in 1811) until very old age (he died in 1875). I'm working on that but am trying to find more numbered and dated rifles.
Bill