I agree it's missing a wood handle. Seriously doubt it's leather related..
I am thinking when you push down on the handle it drops the tang and forces it out. Imagine a woodworking scenario, the center pipe on the bottom rests in a workbench dog hole. You have a couple of boards laying flat on the bench that are slid up against bench dogs. You need to compress the boards and you use this to apply leverage to squeeze them together. Perhaps some custom tool for the furniture industry. The little nubbin on the side of the tang would rest on top of the board. Notice the difference in elevation from where the tool would rest on the workbench to the bottom of the tang holder? Perhaps an inch? Board thickness ?
That's my best guess. :laughing: