Cool! I had never found one before myself. Then I started going to a local forge, became a member of the club, and discovered that they have a whole bucket of them. I couldn't believe it - especially since they were using them to make knives, axes, hooks, and anything else you can think of.
They look to be in great shape - very little rust. Where did you find them? I've been all over the old ex-train tracks in my hometown and never seen anything.