what do you call this fuse?

[1Justin]

Well I'll be wearing the rubber gloves when I pull this one later in the week!

 

[Stroppy]

Best of luck, you'll probably find a nest of Dodo's living behind it!

 

[MikeyT]

Sounds very similar to a C/U swap we did the other week, main fuse cover had no seal and loose - so was partly open to show a fused neutral - and a strap around the sheath which ended up testing to show no connection to any supplied earth.... Needless to say that the C/U was a complete mess in the same cupboard too small for Frodo!

I also got everything upgraded on my house a couple of months ago before I rewired, and just told them it's could possibly be a fused neutral, the guy came out and changed it no quibble for me.