While perusing the factually flawed The Complete Queen, I happened to come over a section chronicling the band's numerous television appearances. In December 1976, Brian appeared on the Old Grey Whistle Test, and John appeared on a BBC program called the Multi-Coloured Swap Shop. Does anybody have a clue what the second show is, and what each band member did on said shows?
The show you refer to was a saturday morning kids show. I was a fan of the show myself, I brought the kids up on it. Can't say I remember John being on it though.
According to the book, it was on December 18, 1976. I read up a bit on it on Google, though it mentioned nothing about John - would be interested to know what he swapped!
Brian was indeed on the Old Grey Whistley Test. They played one track from the 1976 Hyde Park show (I believe it was Sweet Lady, but have to check my video to be sure...) There was an interview with Brian afterwards.
Dunno bout the other show you mention...