You left out the most important part, the top. Is there a hole on the top or no?
That is a rare Wico bat-handle with a metal adapter plate for using it on Midway cabs. They usually have a button on top. Actually, the button is a long plastic stick and at the bottom, below the e-clip there is a plastic disc attached. This disc would push a 5th leaf switch. I don't see that extra switch nor any evidence that the base had it.
So... if the bat has a hole, then it's been inserted into the wrong base. If it doesn't have a hole, then I guess you have a complete, and rare, Wico bat-handle joystick with adapter*.
*That adapter should also be usable on Pacs, Galaga, etc and with any standard joystick with the matching bolt hole spacing.