[Steve in Pudsey]

Also during the 74 elections they keep pointing out that results are on BBC2, telling you they're up to certain letters. Would be interested to see what they actually looked like, but I'm guessing there's no surviving recordings. Presumably it's just the same graphics we see on the main coverage backed by test card music, but it would have been interesting to see.

This is the Genome listing genome.ch.bbc.co.uk 

Results Round-up
In alphabetical order each of the 400 results so far with all the details
- candidates, votes and totals, who has lost his deposit, which former MPs have failed to get back and, wherever possible, the swing to Lab or Con.
On-screen announcements on BBC1 will tell you when your constituency is about to come up Repeat starts 8.15 am

It looks like the BBC1 graphics were generated by the Anchor equipment; the this article from 1972 suggests that it was capable of interfacing with other systems, so presumably a second set of kit could have produced the BBC2 programme. www.bbceng.info 

What it would have been keyed over and what the audio would have been is an interesting point. Possibly a clean, graphic-free feed of the BBC1 programme? Or a generic background with Radio 4's coverage?