If YouTube is any example, we could really do with a professional "remastering" of this short film written by George Lucas. I've gone through many of the "full versions" and they're filtered through YouTube 3D effects, casually converted back to 2D, fuzzy ride videos, widescreen/full-frame, full-frame cropped to widescreen, etc.

Sources SEEM to be, primarily, a screener of the widescreen film, and a full-frame DVD?

Pity people haven't paid closer attention, for example this 70mm film was selling/sold on eBay back in 2011: http://www.ebay.com/itm/220837270580?orig_cvip=true

There's a little more info in this thread maybe: http://originaltrilogy.com/forum/topic.cfm/Star-Tours-Muppet-vision-3-D-Terminator-3-D-Back-to-the-Future-The-Ride-Captain-EO-etc/topic/3438/