FWIW if you wanted to pick the best steel to make an Anvil out of, it's probably H-13. Overkill? Definitely, but you'll never have to worry about spot detempering.
The lack of a real heel on that anvil is particularly appealing to me as a bladesmith. I figure it's easily got the overall centerline mass of a 150-200lb anvil, and it'll be *very* comfortable to get up close on the heel and work the way a non-farrier smith *should* be working, parallel waist to his work, instead of standing in front of the side of an anvil plinking away like a limp wristed dork, swinging a baby hammer like he's worried about a sprain. ;D That's why I prefer a london pattern anvil, and why they have square heels, so you can get your pelvis right up to the heel, and be over your work at the waist of the anvil, parallel to the work, with your hammer at 90 degrees opposed, so your blows near, and far half-hammer face, and full on center, don't twist or distort the work, and allow maximum forging efficiency.
The whole standing parallel to the anvil, facing the side, comes from farriers, who admittedly, brought smithing basically back from the brink of death, but it's become forgotten by most, that there's a reason in their work, why they stand that way, and why, the rest of us, usually, shouldn't.
LOL, two rants in one thread, I'm on a roll?