Paul,
What I meant with respect to the small aperture available for testing fuse-links, is actually shown on the front piece of the fuse carrier in pic No.6, as the little white plugs on the front of the fuse carriers.
But, in a situation like this, these plugs are quite useless.
It's only with Fault-finding 63A+, including 100, 200, 400, 600 and 1000A Mains that I have come to realise that these plugs are only effective where the fuse heating is kept to a minimum, otherwise the plugs turn to one solid mass and trying to get the tip of your Duspol through one of these is futile.
In a Domestic Switch-board, I normally open up the panel and test from the reverse side.
Just saves a lot of time!. [Linked Image]