http://www.pbs.org/wgbh/nova/specialfx/effects/producer.html
NOVA ran a modified version of the doc. The above link is an interview with the producer. The official PBS store used to sell copies.
About a third (most of the Star Wars related material) was previewed at a convention back in 96.. A preservation of that is available on TWC301:
http://originaltrilogy.com/forum/topic.cfm/Treadwell-Collection/post/583697/#TopicPost583697
