That doesn't look like it.
I think it'* an alien device of some sort. Maybe it makes it possible to hook up the tail lights to the spacecraft as they're towing it behind the ship.
I'll get pics. Until then, keep them coming.
I bought it in 1997. There was one owner before me. He was a Goodyear plant manager. The dealer I bought it from sold it to him to begin with and is a good friend of the family. I think he'd have mentioned something back then. Actually, I think I even asked about it a month later or so and he didn't know anything about it.
So, who knows. I thought it was standard.