Cute little bugger! Your call as to devote any more time on it. From what I can disappointingly see (for you!) is $5 for a "foundling" and maybe $10-25 for one that has been cleaned up. As a newbie on here it has already been quite apparent that a chunk of rusted metal with no brand imprint has very little value here. Now it just happens to be I actually enjoy using axes. If this head cleans up and there is a distinct dividing line between hardened steel blade and soft steel body then at very least you've got something useful for yourself. I don't know what the Chinese are foisting off as 'quality axes' these days but likely what you've got is going to be much better. Clean it up, put a handle on, whack it into a tree, and then get back to us.
It is badly rusted don't you know! Rust-hardening (reference to Smokey Unik the legendary stock car engine king that rust-tempered the cylinders of all of his engine blocks) is not at all a negative but this one has definitely taken a lengthy nose-dive and will only be a collector's piece if it somehow says "Michelangelo" or "prop. of Henry Ford" or "T. Edison, Eli Whitney, Oliver Winchester or maybe E. Remington" on it (none of whom made axes, far as I know).