Gentlemen, Thank you for the nice comments. I was very happy when I turned this one over. I have seen a couple in pictures but this was the first to be in my hands. I probably passed 20 other BWBs at the show and never even checked. The reference to Meybauer is from markings on the EK1's. http://gmic.co.uk/index.php?showtopic=20316&hl=meybauer The second cross in this link will show the same device with PM stamped in it. I am not sure that these were exclusively used by Meybauer. Could someone else have patened these and sold them to anyone that wanted one? There is no marking on my badge that I can find. If there is documentation linking this number to PM then that changes things. Thanks, Chet