It had crossed my mind that it may be for a console stick, but see how short the fat portion of the handle is? It's only 7/8" long, and the skinny portion is the standard 1-7/8" long which is the required length to fit through a standard leaf base and doesn't leave any room for a spacer. Which, btw, I've never seen on a Wico leaf stick, the turned down portion of the handle normally rests against a washer directly above the bushing in the rubber gromet.
This means the bottom of the ball would only be about 1/2" above a metal control panel, and that seems way too short for one of the 2600 controllers to me. I could be wrong, but I don't think it is for a 2600 controller.