Oh boy!
The later panels like yours may have more grounds than my 67 but the three I mentioned are the ones I know for the interior.
In theory the instrument board will be grounded simply by mounting it, but at least on mine I found the factory had ground wire from the capacitor mounting screw to the radio support strut. I didn't see cap on your dash. I *think* it may not be needed if an electronic IVR is installed.
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Loose wires - broken connectors. Any of them could have been a short, or a short waiting to happen.