So I have seen a few parts list for the 68 backup switch. They always show the bracket, retainer clip and switch. However, I have seen a couple original setups that include this washer and nut. I included a picture of it.

Does anyone know the correct details and if it was part of the setup. It sure looks correct and really secures the switch. Would it have been on one of the originals 68 parts list and the newer years don't have it?

Anyone have any more details on it?

I know in the picture half of the switch is gone. Just trying to point out the other parts not on the parts list.