Don't get microswitches without lever actuators like the one linked above. They don't work well on the old style stick. It's true that the levers on Cherry switches (as found on Happ Super Joysticks) are too long but it's very easy to cut them to the right length especially since Cherry switches can be opened so you can remove the lever and put it back once you've cut it.
Of course it could be that your problem isn't the switch: it could be the socket contact on the DB15 connector, the wire inside the cable, the faston on the microswitch (possibly also the ground one). You can check all these things with a multimeter (continuity test).
