Looking for interior light

1968 Barracuda has 2 round interior lights that mount on each side above the rear seat and turn on when you open the door.
The passenger side light is wired behind the back seat and connects into the harness with a T connector in the trunk right under where the gas filler tube meets the truck floor.
I have tried buying that light holder, wire and connector to replace my missing one but cannot find it.
Anyone have one or knows where to find one?