Peter Burke wrote:

CU change & rewire is on the way here shortly hence why I am asking. Hager
would be lovely but cost not really justifiable

are Hagar that expensive? an 20-way CU with just the main switch is
about £65, their RCBOs about £24 ea, same sort of price as screwfix for
BG ones.

https://www.consumerunitworld.co.uk/hager-vml120-20-way-rcbo-consumer-unit-1976-p.asp

https://www.consumerunitworld.co.uk/rcbos-234-c.asp