I'll just make a small observation, which I know is not comparing like
with like, but it seems quite amazing to have gone from fuses with a
replaceable element that (in the case of rewireable) costs a few
pennies, to dual-pole RCBOs which cost 70-80 pounds a piece!

I understand the some of the safety advantages - can't replace the
fuse with a hairgrip, RCD is good. And there's the cost of fitting
things into DIN format. It's still quite a contrast.

Sid