I'm pretty certain the above isn't a 'Mystery' to many, but I wasn't certain what to call it. I have a piece of machinery that uses ball handles, that are retained with what appear to be slotted nuts As I was in need of a tool to remove them, and didn't have one in the trusted tool box; well you know what they say about 'necessity'... I'm not implying that I'm the author of this style of tool, as I've seen plenty that were commercially produced, and typically stamped out of sheet steel. I'm just the author of this particular version!
The tool shown in the photos, is made from some 3/16" scrap - hot rolled mild steel. It's really nothing special, and required all of about 15 minutes at the metal band-saw, bench grinder and hand file...
Thanks for reading, I hope you find it useful.