1968 four speed reverse light wiring

Would anyone happen to have an untouched ‘68 4 spd B body that they could take a picture of the firewall bulkhead connector for me?

I put together a ‘68 RR that had been apart for forty years. All new M&H wiring was used front to rear. The car is a late ‘68 with the Hurst shifter with dash mounted reverse light. The ‘68 manual doesn’t have the schematic for wiring the dash light and M&H doesn’t know how to set it up either. As of now, I can get the dash and back up lamps to light up if I put the one “extra” lead coming off the new back up lamp harness to the starter relay battery positive terminal, but they obviously won’t turn off that way.

Any help would be appreciated 👍

The back up light switch is either open or close to conduct the current to the light bulbs, I believe it is fed of off of the ignition switch in the run position.
I have a 1969 Dodge FSM in the shop, I'll look at the wiring schematics in the morning and add onto this reply tomorrow sometime tomorrow
My 1966 Dodge Deluxe Coronet has that same wiring in it for the back up off of the original 3 speed on the steering column minus the back up light on the dash.

Take a look here. https://www.forbbodiesonly.com/moparforum/threads/b-body-4-speed-reverse-light-wire.64374/

In the thread above there is a scan of the '69 FSM wiring diagram. The return from the reverse light switch on the 4-speed in the engine compartment goes to top connector cavity "C" as normal (this would connect to the reverse lights at the rear of the car, but with the 4-speed interior reverse light, there is a jumper than connects cavity "C" to cavity "Z" on the bottom of the bulkhead connector.
Then the inside "Z" bulkhead connection connects to the interior reverse light.