These paddles are made from beech wood, rubbed with bee's wax. They
are meant to fit a newer (post WW-II) Vibroplex. The hole spacing is
7/16 inch, and the edge hole is sized to pass a 6-32 screw, while the
inner one is sized to a close fit for an 8-32 screw. These could fit
classic Vibroplex products such the Original, Champion, or Lightning Bug
or even homebrew keys. Some adjustment of hole size or spacing may be
needed in your non-Vibroplex application. Shown in the next 2 photos is
what a typical paddle looks like on an Original. The key is not included
in the sale, of course. The next two photos show my setup for making the knobs, while the last few are of some other styles of paddles/knobs I have made, the last a custom job for a ham colleague. Email me if you have any questions and thanks
for looking!