Rally Dash Wiring Harness Questions

I would look for at least a 1970 wiring diagram. For 1970 up, ignition switch moved, flasher switch moved, along with many other changes. The 68 model bulkhead wire positions will not be the same. Even 67 and 68 differ. anyway...
Rallye inst' panel has 2 circuit boards with illumination bulbs in both, so the orange wire has to go to both. If you cut into a rallye dash harness you should find a weld splice where the orange wire coming to the standard/round terminal is weld splice branched to route to the other board connector.
As for that brake lamp black wire, it goes to the brake warning switch on proportion valve. Whatever position is placed in outside bulkhead connector needs to match the inside bulkhead connector.
Now about the 12 volt supplied to a voltage limiter. In pre 70 builds, blue w/white tracer from that ignition switch connector was 2 wires in one terminal. One of those went to the round panel connector to feed the limiter located inside that fuel gauge. Note that the limiters were not fuse protected.
I honestly don't know where these ( standard or rally ) got 12 volts supply to the limiter for either limiter location. I think I have 1970 factory service manual here so I could have a look.
Smaller wires as branches away from a larger wire, consider that the trunk line... 1 or more 18awg weld spliced to one 10awg was common.
So a rally panel gets power to its limiter through the 10 o'clock position of the round connector. As long as its switched 12 volts it doesn't really matter if its tied to black or blue w/white after ignition switch with or without a inline fuse.
I do think the later model diagram would answer most of these questions.