Hey Kirby,
Stic is right, should be pretty hard stuff. A right angle grinder with a metal cutting wheel is one of the cheapest, easiest ways to cut it up to sizes you can handle.
After you do as Frank said and soften it, the grinder with and thinner (1/16" or so) cutting wheel will make short work of cutting out the blade blank.
Those things have been made out of a lot of different steels over the years, but they all have one thing in common. They have to be heat treatable to around 40-50 Rc. That means it should be at least a 1060 steel, but it could be a high grade carbon/alloy spring steel too.
If you're concerned about the grade, do a spark test. All you have to have is a grinder that turns 10,000 rpm. Basically any right angle grinder. And if you do an internet search you find info on how to do it and probably even some pics for comparison.
But like Frank said, should be pretty hard and it may make a great knife. But you'll need to cut it up and soften it first or it'll work you to death grinding and finishing it. ;~)