[Lynn Eades]

Tom, your number plate board should have a single hole at the top for a light. It will either be the "early" rubber light or the "later" small metal type.
There should be a change over switch, to switch between the black out light (facing the diff) and the tail light.
If you wade through Jordan Baker's very good, and comprehensive thread on his carrier rebuild, you will learn some stuff (lots of stuff!) about your carrier.
Then all you will need is for someone like Michael R. to chime in with the change over date of the lights, and you will have what you need.

As always, pictures would help us to understand what issues you might have.
Or to quote Tony, "this thread is useless without pictures".