I thought there were and they did?

JEDIT:Artoo’s panels are still black in the DS battle, but I always thought they turned black when in outer space for some reason.

And dead Artoo still has black panels when Luke returns to the base, supporting my theory. 😉

There must be a reason the Y-wings don’t have R2 units? Even the Kenner die cast toy has one.

I swear photos I’ve seen of the original models have them, but they could have been added later?

The design of the Y-Wing cockpits would make it impossible to see the R2 units behind the pilot even if they were there.