"John Miller" wrote in message
...

Many thanks for your trouble. It didn't work too well in my browser either
but the jpeg is clear enough and these fittings look as though they'll do
the job I want. It's quite a clever idea and it seems a pity that
Screwfix
sell it but don't have a clue how it works. Not sure where I'll get a
47mm
spanner, though!

Mm, Screwfix don't sell them, that's for sure! But if you search the site
on "wrench" (as opposed to spanner) you'll find a number of adjustable items
which should work OK.

Good luck with it
David