Do you plan on selling cut down n64 mobos to other members?
I would love to but have very little time at the moment. Possibly in the future.
Is that wire wrap wire? Also, what are the two extra chips on the N64 motherboard?
Yes it's wire wrap or kynar wire.
The two chips are just logic gates for the intergrated screen controls.
did you just connect the middle leads of the pots from the C-stick to ground and used the other 4 as a switch (with additional resistors to ground to make it more sensitive) or did you use a more complicated method?
Yes. You've got it. That method works with an official N64 controller.
When I originally tried this with the gamecube stick, the resistor values needed were 6k8 ohms. But I just wired up a psx stick (also a 10k pot) which needed resistors of 8k2 ohms. You may need to experiment with values.
However, I was unable to recreate this with the 3rd party pad I'm using. The controller would register a button press with a very small amount of current flow and the 10k pot was too 'narrow' resistance wise, to make a clear on and off. So I had to use the pot as a potential divder with an LED bargraph circuit that would switch the buttons via transistors.