RayB- That square actuator is for microswitch-based Wicos, like those ones I sent you for your firetop handles way back when.
Sorry, Timoe- I've got plenty of 8-way bases, but no spare 4-way ones. Sometimes you can get somebody who wants a NOS 8-way to order one of the NOS 4-ways on ebay, and then swap the joystick bodies.