I reworked this joystick last year, from old sound port to USB, of course I used MMJoy2. Explain to you all theory about MMJoy2 and how to work electronics, sorry I am very busy. But all necessary information you can find on that forum.
Look at my post and pictures only for your inspiration:
If you have some specific questions about this reworking I am ready to answer you.
Good luck
Thanks again for the Help you gave me Last year during my Conversion Erichos , it was invaluable , I would never have figured some of it out by myself...