What I did and I'm just wanting to check that this was a legitimate thing
to do was to use a 15amp chocolate block to combine the mains cables
together (3 live into one and 3 neutral into another) I then got some
ring mains cable from homebase and used a few inches of this to connect
the chocolate blocks to the feed of the fused spur.

Is this ok?

Sounds fine in principle, although I would probably have used 30A chocky
blocks.

Thanks Dave and John for the replies.

I do tend to be cautious when it comes to electrics - as an example because
of this deviation to the 'normal' wiring I've just ordered wylex plug-in
MCBs to replace the rewirable cartridges in my fuse box. I do want to
replace this with a modern split consumer unit with RCD but funds just won't
permit this just now.

I was wondering about the rating of the choc, as when I checked the quantity
and rating of the fuses (to order the MCB equivalents) I have three 5 amp,
one 20 amp and two 30 amp.

Do you think its worth while replacing the choc block with a 30 amp?