Ding Ding Ding looks like we have a winner. Watch makers truing calipers it is (I did all kinds of internet searches before asking here and couldn't find anything). I will be seeing Chris next week and I will ask him about his Dad ever doing watch work. I know from what he has told me he was a good machinist and built muzzleloading rifles, lock stock and barrel. I've seen his work on those. Forged all his lock parts and hardware and turned all the screws for all of them. In fact I helped Chris sell the rifling machine his Dad built and am the proud owner of some of the tools he built. Beautiful work. Chris gave me a ton of his stuff for helping him clean out his Dad's garage including a whole tool box full of taps, dies, and reamers. He also gave me a drawer full of new, still in the box files of about every shape and size you could want. I bought the Kennedy box with his machinist tools in it if you want to call $100 buying it. His price not mine. He said he wanted them to go to someone who would enjoy them and use them.