About this one !!
Here is possibly the most difficult one we may ever see, I bought it for a dollar from a tool vendor in a little flea market down in NC who also had no idea what it was. He had it there for a while and no one ever had a clue. I can't come up with anything.
The rounded end inside the spring loaded jaws goes forward and back but only as far as you see in the photos, it's just enough to open the jaws a bit.
What really threw me is the drill bit attached to the screw in knob at the very back, it seems to have nothing to do with anything.
The only marking on it is JAPAN on the flat of the screw end
