83mvp,
Ruger and His Guns probably has the best info; there is a picture of an Alexander Henry rifle from the WBR collection with the comment that this was the inspiration for this Ruger No.1 forearm.
The 1st Ad(1967) states: "Two forearm styles are available: a short slim type in the classic style of Alexander Henry---and a longer semi-beavertail style."
I would need to check my resources for certain, but I seem to remember that in the very beginning this forearm was termed the slender sporting style; and shortly later, the Alex Henry style.
I remember when they first came out, I did not care for the appearance of the AH. Later, it kind of grew on me and now is my preferred forearm!
