Denny,
As odd as it sounds, the originals are upside down on an AD. I have two original right hand lights,(one is NOS in the box) and they are upside down compared to the left.
Myself and a couple of others determined that GM probably did not re-tool the right light when the AD's came out. The 40-46 used a left taillight bracket that held the license above the lamp, so the right lamp would be oriented the same on those years. When the AD's came out, they flipped the left light, but apparently didn't do the same with the right.
Also, a plastic Guide lens is the correct lens for your year, but the clear license lens is glass.
Bob
