Thanks, I will have a look in the book, but I've got a feeling that they are not the originals as when I had a puncture some time ago, the tool-kit wrench would not fit the lock nut. My local tyre place is very resourceful and they have managed to get one off without any drams, just have to hope that the other three will be the same. Meantime, it's nuts I need :-)
By the way I've been unable to get a quote from Longlife Northampton, but did get a decent one from Tony Banks in Leeds. Looks like a day out in Leeds is on the cards, but I'm not in a hurry to spend money as (touch wood) the weld is holding good ....so far!!