I think Nacho is right, for example I do not think Road Runner came with Light on option, even though it can have A01. Yet a Belvedere could.

The Buzzer you showed actually looks more robust, then the one I showed.

I will say, there is one more oddity in the Plymouth service manual. One of the relays, maybe E shows resistors inside the relay on the drawing. I know the 872 does not have any. SO maybe that resistor is in the other relay, and does help prevent any feedback if you have the Light on option, or Light Delay option, that some models had with the A01 package.