Just to cut to the chase, barring a very detailed and convoluted detective chase, this is ultimately the conclusion:

This crude gif is a comparison between Zion's 1977 16mm print, which is clearly identical to the GOUT and the SE (minus the optical matte line on the star destroyer and the coloring of the moon, both of which are on the GOUT) and Moth3r's 1981 shot, which I'm sure all will agree is the most apparently different version, and thus, if this can be shown to be the same as the 1977 then all others should be as well. I cranked the contrast on Moth3r's to get the low-con milky blacks closer to the film print and also to really bring out the shading and texture of the moon's surface to more clearly show the detail.

I think what you'll find here is what I said earlier: the 1981 moon is the same as the 1977 moon, only stretched horizontally, and with smeared detail due to the poor technology of laserdisk display and capture. Also note that this comparison is not the same exact frame as the film print, merely the same shot.

1977 VERSUS 1981