The first BBC TV "live" 500GP I can remember was the 1979 Barry Sheene 'waving' at Kenny Roberts, less than a wheel between them @the finish GP..
In 1983 they showed the 250 & 500 race live, & 125 last few laps live, not being a "mainstream sport" M/C racing always played 2nd place to Horse racing,
One year the BBC were showing the Transatlantic trophy (that was the plan anyway!!) live on BBC2, but for some reason there was a long delay at the track, anyway after watching assorted pitlane shenanigans,(people sitting around mostly!!) the two teams went out on their warm up lap, formed up on the grid flag drops & as they race off to Paddock Hill bend, Murray Walker uttered the imortal words " I am afraid thats all we have time for now"!!! and Childrens TV programme "Playschool" came on!! Frustrating that was, but quite amusing at the same time!!
I agree about the red button for 125/250 (whatever thats going to be called now!!) uninterupted coverage and a reasonable commentary team.
Then MotoGP, I still watch BBC coverage for that, but prefer Julian/Toby commentary, though Charlie/Steve were pretty good, I know a lot of people dont agree, but they are better than that screamer Jonathan? Green, blooming awful he is!! I rather watch Horse racing when he does the commentary!!