So you have a Gravis GamePad! Very cool. But you're missing the joystick like everyone else. Maybe you've got an old 8/32" bolt screwed in that you use instead, which is nearly as uncomfortable as the original stick.
But now, there's a solution!
The original joystick has plastic threads which screw into the gamepad, but these would be quite fragile if 3D printed. Instead, there's a 0.6" deep hole in the model where you glue in a 0.75" length of threaded 8-32 rod. Or just get an 8-32 screw and cut the head off. It should protrude 0.15" below the bottom of the joystick handle.
Enjoy!