For that purpose I'd put BS 1361 (Type 2) 'cos that's the usual type of
supplier's fuse and won't raise any eyebrows. I presume it has smooth
round end-caps with no projecting blades or bolt lugs(?). It's quite
old, that fuse, have you thought about treating the cut-out to a new one?

Yes. It has smooth end caps, like a standard HRC fuse. Presumably it
isn't up to me to treat it to a new fuse. That is, surely, the
responsibility of the electricity company?

Christian.