You could of course have a stand-alone RCD unit, situated just after the consumer unit.
What are you thinking - a 6.5kW shower?
I would not recommend fitting a shower without an RCD nowadays.
I was looking at some old plastic MK consumer units I fitted getting on for 20 years ago (it seems like only yesterday) and marvelling at how discoloured and shabby the look now.
Which rooms have the battery only rf detectors?
Has a bungalow extension been added recently?
Trying to figure out why the mains ones have become redundant - especially because it's usually easy to add more mains detectors in a bungalow.
Is this just not conventional conduit wiring, with a neutral in, and neutral out, and a switched live?
Can you see another continuous red wire simply running from one conduit to another conduit in the round circular ceiling box?
That's a hell of a lot damage. Being a dot and dab wall, a lot of the cable could have been fished behind the board, and chased only where a dot is.
Still, not my problem.
I don't see any need to label unused cores that have been terminated in connector blocks.
If there is only one wire in the connector block, it's fairly obvious it's spare - or at least, 'not doing anything'.