1966 Barracuda Lower Tail Light Lens
I do see a very slight difference between them. If your buddy points out your error....he's not really a buddy at all.
I have an "L". It has a little depression in the middle from the bulb being too hot, I imagine, but very nice otherwise. You could try the careful use of a heat gun...but I wouldn't.
If you want it, P.M. me