That is an absolutely fantastic clip - what a shame that a full Beeb archive version in quality video and sound isn't available. I guess we are fortunate that it survived in any form though..
Talking of Ronnies and Big Bands - I was in the audience around 1980-ish during a performance of 30 minutes by either Woody Herman or Buddy Rich (pretty sure it was Herman but it was a long time ago) just before the main sets, introduced by RS, which was broadcast live on BBC2. To the best of my knowledge, it has never, ever been repeated.
John Surman/John Warren 'Tales of the Algonquin'?