Japanese 17Th Century Tanto Sword

This tanto is very old, at least 17th century, most likely older still. The blade has been polished many times over the centuries and has lost thickness and depth as a result. Only traces of the hamnos remain and the tang is unsigned. The blade was in a sorry state when purchased and has since been hand polished. Some fine pitting remains on one side of the blade, the other side is fairly clean.