March 23 at the back. Is there a way to ID the year? What does 11 on the water outlet mean?
March 9 at the back, 6 on the water outlet. Otherwise the same as far as I can see.
Both of them are 1913 - 1917. No way to date them any closer than that Steve. The number on top of the water outlet area is the mold number.
There was one change registered in July 1914 that may indicate whether they're '13-'14 or '15-'17 style? :
"07-17-14 T401C Added 3/32" to bottom of head, increases all top to bottom dimensions and lowers compression."