Roy Trumbull has recovered some rare Yippee! movement footage: "In the wake of the demonstrations during the 1968 Democratic Convention in Chicago, the city produced a white wash entitled 'What Trees Did They Plant?' TV Stations that broadcast the film had to offer equal time to those speaking in opposition. One group was the Youth International Party or Yippies who produced this film. Paul Krassner wrote the script. Some classic film footage was re-mixed with footage shot during the demonstrations. Paul Krassner wrote the script but otherwise there's no traditional credit list. It's hoped the original film still exists and that a better copy can be posted.
At the end of the film there is a credit for additional footage to Killian Shows, Inc and a production credit to Documentary Interlock, Inc. However a search doesn't turn up a connection with current companies using similar names.
The pitchman for the Yippie helmet was Marshall Efron. The Yippie head was that of Bob Fass.
Keith Lampe was the narrator."
Update: Roy adds, "I heard from someone who knew where a totally pristine copy was posted.
From the looks of it the copy on this site was made from the film as originally edited. The version I have was as broadcast by Metromedia TV stations.
The most obvious difference is in the last scene with the pig where Mayor Daley's face is intercut with the goings on. That is followed by a promo for the inauguration of the pig the following year. On my copy Daley's face isn't there and the promo is missing. Those were probably some concessions made at the last minute."
The Yippie Response to Mayor Daley 1968
(Thanks, Roy!)