Its just an old herters pop eye jig mold 4G2 . I resurfaced the inside so it would close tighter and then drilled it for a compression fit to install a flat head rivet. Came out better than expected with a perfect recess for eyes. Thats a 1/0 413 hook in it. It will accept 90* or 60* hooks. Roughly 1/4 oz. Thought you might like to know in case you want to make one.
Heck Oklahoma fishing ain't what it used to be. Unfotunately I've never got to see anything like a hammer head except in an an , aquarium much less fish for it.