I have a very early (1956) X50 that is complete and all original but is missing a tone knob. The volume knob has no markings so I assume the tone knob would be the same. So far I haven’t been able to locate one on the web. Just wondering if there is some arcane parts source that might help in my search, or someone in this group that has any. I love the X50, the first guitar I ever played, and now one of my favorites in my collection.