Sorry, I didn't say I already looked at all the happs analog joystick exploded views looking for a pin out, or at least some info on how many pins and how they are arranged.
I was hoping for a pic of the harness, especially how it hooks to the base, and the plug end.
Just guessing, I'd think the analog side has four wires: gnd, 5v+, X axis, & Y axis, but there could be six with each axis having its own gnd & power inaddition to the sensor wire. And the buttons end has three or four wires (assuming two buttons on stick): one for each button, and one common ground or two grounds with one for each button. But I'd need more info to give you better info.
Or are the POTs not hooked up to any wires, and you are asking about how to wire directly to the POT? The POTs should have three connections: the middle usually is the one for the axis, and the ends usually are for ground & power.
OT, how do you like the handle? It looks... I don't know, like the guard is an added afterthought?