Interesting Yarifish, Lee! The carving’s stylized realism incline me to agree with the trend of the thread in thinking it was modified somewhere close in to Japan. I don’t think I have ever seen a fish face carved quite like that one, if I do I’ll let you know.
Gav, if the auction photo above isn’t making it clear, you’ll have to take my word for it – there is no resemblance to a hachiwara in the form of this item.
The curve of the blade was damage done long after the piece had ended its useful life, the associated edge damage is very fresh and indicates five or six strong swipes at an immovable object in the hands of someone unfamiliar with edged weapons; a cluster of them too close to the grip with a few wild blows as the destroyer found his range. Really, more tragic than the cut down tang.
Evidently, the spear saw significant service as a sword, the forward edge has been re-sharpened enough to bring it a sixteenth of an inch (1.2mm) closer to the ridge than the back edge in the area of the center of percussion.