No clue what this is, maybe a buckle or hinge of some sort, but my new Xmas gift, Pioneer 505, found it first time out sweeping the back yard, pretty heavy for the size, and was about 6 inches deep, right about where it said it was and how deep it was. Don't care if it is worth anything, to me its my first find, and i am assuming its old , due to depth, and can only imagine the pivotal part this played in history