This silent documentary, shot mostly from the unfinished side of the Sail Barge, was made by a gentleman named Jeff Broz. According to SyfyWire:
Imagine being a fellow with an 8mm camera in the ‘80s, running around Buttercup Valley in California and stumbling upon the set of a movie. Imagine that film was Return of the Jedi. You just start rolling and make yourself a nice little documentary. That’s exactly what happened with a fellow named Jeff Broz.
My initial thought was that this video is soon to be shut down by LFL, but it has been posted to YouTube since 2012. Check it out: