Dash Wiring Issues

Apologies in advance for all the Mopar rookie questions :)

I'm trying to chase down a dash wiring issue in our '64 Dart, specifically there are no dash lights and the fuel and temperature gauges sometimes decide to take a random little vacation together. I downloaded the wiring diagram for the '64 Dart from mymopar.com but it's incomplete. Is there another good resource for wiring diagrams? Are there any known / common fail points? Also, is there a dash ground somewhere? I looked around but didn't see one, unless I overlooked it. Totally possible, me with my bad back trying to work under there.....

What is incomplete about it? Accessory wiring is shown in the service manual under its particular section.