Finally had a chance to take some (hopefully) better photos of my two backglasses. First, the thickness:
As you can see, they are the same thickness... so presumably they're from the same supplier or whatever.
Now, a better comparison of the graphics. My original, worn one is on the left (I got it signed by Steve Ritchie at Louisville this year, in the bottom left). The OEM NOS is on the right:
At a glance the big differences are the NOS has more yellow in the explosions, deeper blue wings on the spacecraft, and a better fade behind the title marquee. More subtly, the NOS does NOT have that faded "gray" area at the 11 o'clock position on the "eclipse", nor does it have the faded gray edging the left of the explosion on Player 3.
Now, comparing to the Mayfair Repro by borrowing a photo posted earlier:
We can see the repro retains the gray areas, loses the fade behind the marquee in favor of a solid orange, and also seems to lose some blue in the spacecraft (cockpits, for example).
Anyway, it probably doesn't make a huge difference in the long run, but I tend to be OCD on this kind of stuff... guess I played too many "spot the difference!" games when I was little. But it's interesting that there are these variations in the first place! I wonder which ones are most preferred...?