On Sun, 16 Mar 2008 16:26:59 +0000, John Rumm
wrote:

Much depends on the state of the cables. A '30s place could well still
have rubber insulated wiring and urgently need rewiring.

It could, but as it already has MCB's that is very unlikely. Even if
it was rubber it might well not even be picked up in a Periodic
Inspection Report unless its somewhere it can be seen without lifting
boards etc. PIRs are far more of a customer paid for sales
opportunity for electricians than anything useful.