Seen this before, but still interesting to watch. Non-sync cuts and the picture flying all over the place every time they cut to somewhere else, most OBs are still in black & white, and every now and then the picture fades out and fades back in a couple of minutes later- presumably while tapes were changed. I'm guessing in later years there'd be more than one machine and overlaps at tape changes so no footage was missing, but I imagine VT machines were still at a premium in 1970 so they'd only be using one.
Noticed one occasion, where they cut to another source while a result caption was on screen, and the caption flew all over the screen as well, I presume the non-sync cut messed with the capgen.
Brilliant as he was (though I only remember him on the Holiday programme) Cliff Michelmore feels a bit too breezy and larks about a bit too much for an election programme.