The original CU install was done in 2012 by a clearly competent (or at least neat) installer (though one of the RCDs was labelled Time Delayed, which confused me at first since it isn't.
Originally a 6mm feed to a shower in the bathroom, which was adjusted down to 20A and then 2.5mm connected in a brown junction box in the loft to run to the boiler...
It was clearly a rewire done at the cheapest possible cost at the time - 80s white cabling cut and left, alongside the original 30s fabric singles in metal pipe in places - run over joists in the loft, etc, single sockets replaced at an angle, etc.
CU was neat though!
Fortunately I keep old MK breakers in the van so was able to put a proper 20A in there at least.
Took me longer to retrieve the busbar from the 3 foot drop under the floorboards where it immediately fell when undoing it ? I was there for 15 minutes with a rod and hook like a bloody fairground machine!