Many of the theories as to why there was never a promo mtv style video of KOP are correct. ie No time, not intended to be a single, became a hit on it's own etc.
As for the videos that were recorded, Synch II was not filmed at The Chaplin stage. It was filmed at Shepperton Studios in Surrey. I wasn't present at the shoot but from what I understand the tower of detritus and equipment, that the individual band members performed, on was adorned with gear from the WHO's storage locker which was located at Shepperton.
TheEqualizer - "I love the Synch II video because of the way STEWART just BASHES his snare."
In actual fact the snare Stewart is bashing was most likely one of Keith Moon's snare drums from that same storage locker.
KIM - There were a lot of smoke machines on the set and I believe some of the detritus may have caught fire, adding to everyone's displeasure.
English-lion - The video you posted was a clip from The Kenny Everett Television Show. It was recorded at the show's location in one of the BBC studios, possibly in Sheperds Bush.
http://en.wikipedia.org/wiki/Kenny_Everett