the headlamp warning buzzer in the above wiring diagram I posted is what I am also wondering about.

It's the grey female 2 way connector - seen below top left. Approx. a foot above the bulkhead connector or approx. 6 inches above the turn signal and ignition steering column wiring connectors. The diagram shows installed w/ male 'diode.' This isn't the key in buzzer harness connector previously seen in a few of the other pics already posted earlier.

Was this connector used for anything as the diagram suggests, or a late decision to not use and make the key in buzzer also the headlamp warning buzzer?