I bought an RE Davis English head in 6150 and reshaped it a bit a couple years ago. It isn't quite symmetrical, for one thing - it looked to me like they reproduced the irregularities of whatever forged model they used. It is pretty heavy for a fighting hawk, IMHO, though that might be a feature if you intend to use it as a tool, but the real issue in my opinion is that the eye is pretty small, intended to fit commercial handles for throwing hawks I think. It hardened up just fine, though I haven't ever used it for much chopping.
Jim Chambers has cast tomahawk head blanks for sale too, with an eye big enough for a good stout handle that can have a drilled hole and yet not break under real use. They are blanks, though, big enough to be filed to whatever shape you desire, but as such require a considerable amount of metal filed away before they are useable. I started one but have never finished, partly because of poor technique on my part that will be hard to correct and partly because I uncovered a pin-hole that seemed have a lot of oil inside, leading me to suspect that there is a bigger void in there that may show up in the most inconvenient way. Still, for someone who wants something different, it is a better prospect than trying to customize a Davis head, I think.