I have been looking and I can't think of any thing and I haven't found any thing that matches. It could be a tool that was made for a one time use or purpose. I have found a bunch of stuff like that over the years. I'll keep looking
could be a garden hoe as matt said , remember these were not machine mass made back then and were usually BS made , and depending on what the blacksmith thought was the best design is what he made .
here is a couple different pictures of antique hoes .