This is a remix of Schrodingers_cat B8 Flight Stick shift knob. I needed M8x1.25mm threads for the automatic shift knob for my Toyota 4Runner so I edited the original file. Use the original version for the trigger and knob parts.
For push buttons I used standard 12mm mounting thread momentary buttons. You may have to open the holes up a bit to make them fit. For the joystick directional pad I bought replacement joysticks for the xbox one controllers; just the switch portion of it. You can find both of those on amazon.
The trigger I am using an old spring I had in a random collection of stuff I had in the garage and the pin is a 1/8" roll pin. You may have to open the holes up a bit to fit one that size though; I did.