Some additional notes:
The Rutles first appeared on the BBC television series Rutland Weekend Television, (AKA RWT), season 1, episode 3. The original broadcast was on May 26, 1975. They also appeared in season 2, episode 1of RWT, (November 12, 1976), and at least one other episode in between these two; there were two seasons of RWT, with 7 episodes in each.
The Rutles first appeared on US Television in October 2, 1976, on NBC's Saturday Night - This was the announced name of the current show Saturday Night Live for its first two seasons. The ABC network had aired a sketch comedy/ variety show named Saturday Night Live with Howard Cosell during the 1975-76 television season.
The original broadcast of The Rutles in All You Need is Cash, on March 22, 1978, was the lowest rated show for that calendar week, (at the time, there were only three US television networks, ABC, NBC and CBS).
The Bonzo Dog Doo Dah Band performed the song Death Cab for Cutie in The Beatles' television film Magical Mystery Tour, (originally aired December 26, 1967).
The Wikipedia page for The Bonzo Dog Doo Dah Band contains information that I added personally, as an editor. I added the information about their television appearance on the December 31, 1968 episode of Beat Club.
I have several Wikipedia page editing credits. The one which relates most to this board is in the filmography of Cynthia Wood. Cyndi was the February, 1973 Playboy Playmate of the Month, and 1974 Playboy Playmate of the Year. I added the information that she played the role of "Playmate of the Year" in the 1979 film, Apocalypse Now.
FYI: Anyone can be an editor of Wikipedia, but most people misunderstand the site's intent. It is not an online encyclopedia. It is a repository of information, believed to be factual, which can be cross-referenced through links to other reliable online sources.
If you were an eyewitness to an historical event, and had unpublished video evidence which supported your story, it would not be published on Wikipedia. When I edited the information for The Bonzo Dog Doo Dah Band and Cyndi Wood, I provided cross reference links to youtube and imdb, respectively. In another situation, I had a full list of the performers on the 1978 ITV UK music TV series Revolver, as well as physical copies of each of the eight episodes, but that information was not added to the page, specifically because it was not published on another reliable website, so no cross reference link existed. I did, however, reach the appeal stage - a retired Wikipedia editor who surfaces about once per month to make yes/ no decisions on unusual situations such as this one ruled against me.