Lastman:I would have thought the electrician would just be able to replace the circuit breaker on that circuit with a surface mount rcbo. Would entail running a neutral to it but doubt the whole board would need replacing or a particularly big job.
Depends on what your fuse box currently has, if it's a modern DIN-rail one then it's pretty easy, if it's some ancient ceramic-fuseholder-screwed-into-Masonite setup then you'll probably need to get the whole thing replaced.
