you got to be careful with the high carbon steel, things were much simpler in the 1860's, not such a selection and the blacksmiths were used to what was available then.
It is a funny thing about steel if it is too hard it becomes brittle, and not really nice to work with
A good axe's cutting edge needs to be hard but just to the point that you cannot file it easily, something like saw steel. If you try filing it, it will chatter, and make a screeching sound, but will remove some steel--and will hone up nicely near the end, and hold the edge
