Need Help Identifying This One

[jbravo]

Just taken in trade, this is a very sharp cleaver with a canted handle, 5" cutting edge, cord wrap over rayskin full tang handle, and a heavy leather sheath. There is a triangular piece of abalone in the handle as a menuki, the tang shows the marks of a forge hammer, and the blade appears to have a thick patina. I'm sure its a handmade piece, excellent work, but cannot find a makers mark of any kind on it. Any ID info greatly appreciated!