Thanks again for the kind words, guys.
Further to John's response re the two rings around the bowl, I was always led to believe that the reason the tradition persisted is that they help to cool the bowl, although if that were true I think we would see them on other shapes, as well. And BTW it was the beauty of John's pipe that made me (I had no choice!) ask Dan at Gabrieli to create a variation on the theme.
Andy