3 Lights or 2, What Models?

I'm having a friend pick up rear tail lights at a wrecking yard ($925 new). On the lesabre, some have 2 lights and some have 3.

It seems like maybe the difference could be "custom" and "limited" where one has 2 and the other has 3. The problem is i don't know for sure.

Does anyone know if a custom could have both 2 or 3, or if its between custom and limited?

thank you,
Chris