I did something similar as a kid on my Commodore 64. When my Quickshot joystick broke (after playing Summer Games and similar), I took it apart - it was then t

I did something similar as a kid on my Commodore 64. When my Quickshot joystick broke (after playing Summer Games and similar), I took it apart - it was then that I realised it was just simple switches - it was a metal dome over a circuit board. I'd re-bend/pop-up the metal dome which would make it work again for a little bit. Understanding it was switches, with a wire, I worked out & documented the pinout of the DB-9 connector (afterwards, my father showed me it was documented in the C64 manual). At some point, I took the remote from an cheap broken RC car, and soldered the switches from it to the cable of a broken joystick. I found a switch in my father's parts bin for the fire button. It worked, but it wore out pretty quick - the RC car controllers switches weren't built for gaming use! I wish I had photos - its long gone.