Muppets, The Dark Crystal, & Brian Froud RARE video

This rare 3-part (silent) video from 1978-79 reveals the action behind-the-scenes at the Muppet Workshop in NYC as Brian Froud and craftspeople create the puppets for the movie "The Dark Crystal".
Screen tests of the puppets in action were shot on location (behind Jim Henson's house in Connecticut) and in a rented NYC studio.
Produced and Edited by Joe Tripician with camerawork by Merrill Aldighieri.
NOTE: There is No Audio on this video. It's from the only copy I could find.
UPDATE: Henson Associates publishes my handwritten log from these screen tests: www.henson.com/...