The dating is a little tough on this one. I previously stated that I thought it was from 1925, but it lacks the "Inner Tube" stamp I would have expected in 1925. Also, the fishtail mouthpiece suggests post-1920s. The numbers on the shank look like underlined 3 following the patent and underlined 5 closer to the Made In stamp. But the underline beneath the 3 looks too long, like maybe it was 13. The stem looks like it has TWO patent numbers to me. One may be 5861/12, which ran from 1913-1927, and the other 1343253/20, which ran from 1927-1942, while the patent on the shank is 116989/17, which ran from 1918-1934/5. The overlapping years would have been 1927-1934/5. So, I am guessing that this pipe was made in 1933 and sold in 1935. However, that doesn't quite work, either, since the "Inner Tube" stamp persisted until 1935. So, why would it be missing from a pipe made in 1933 and sold in 1935? Still, my best guess is now 1935.