As pointed out in: http://originaltrilogy.com/forum/topic.cfm/Ben-Burtts-Special-Effects-Anything-Can-Happen/post/583695/#TopicPost583695 the PBS edit of this doc was available for purchase from the PBS website, many years ago. So that VHS/DVD may show up someday on reselling websites.
The TWC301 preservation contains most of the Star Wars portion of the doc, as shown at a 1996 convention hosted by Steve Sansweet.
TWC289 also has a piece of the doc as broadcasted by various news programs.
Storyline - 02 - Star Wars IMAX/Special Effects 32 - Turner Entertainment Report Hollywood - IMAX/"Special Effects" (pkg) Produced by: Linda Mour 33 - Turner Entertainment Report Hollywood - IMAX/"Special Effects" (vosot) Produced by: Linda Mour
Here is a comparison of the redone opening Star Wars scene from the two Treadwell Collection discs:
TWC301 - 1996 Convention
TWC289 - 1996 News broadcast package