I got the schematic all done up.
I also took apart a game pad and took some calipers to it for the dimensions of the PCB. Dunno if my calipers are off or they used imperial dimensions.
I plan to use the 805 footprint for the resistors.
Before finishing up the PCB I need to breadboard the schematic or make a crude protoboard of the circuit and make sure it works. I don’t want to yolo it and wait a few weeks to find out I screwed up somewhere. After I test and tweak the circuit I can then order a set of 5 boards and if they pass testing I might order a hundred of them and sale them on eBay or something.