Easy peasy. It was the rhino skin on my mechanics thumbs not responding. Lucky I have two teenagers in the house to care for (laugh at) me.
Amateur question. Can't you just wire L and N through their own single pole breakers to give the same result?
Yep that's the one I got, we could do with a link to one with B breakers on double pole though (I'm risking the C for now)
Just get one of these compact dp mcb and a good price http://www.xtremevan.co.uk/index.php?cPath=721_737