As above, some of these cutouts may be in a bad way, I have had this before where I had emergency out and they turned up and wouldn't even touch the cutout as they were considered too dangerous to try open live... these things don't just give a little flash bang, dependant on network layout these things can go with more of an explosion.
I believe there is some area's of the country that the DNO allows a registered company to withdraw a fuse for a board change and notification but I believe you need to do an awareness course first, it might be Scotland where this scheme exists, I'm sure someone will clarify that although I believe your still not allowed to replace blown fuses as it can be down to faults in the cutout (loose terminations etc).
It is what it is, don't take on the possible liability and look more into the reasons why a cutout might be taken out due to the consumer side and advise accordingly.