I use a balancing stand made from shelving angle. The angle is
about 1.5" x 1.5" and has slots that allow you to bolt together just
about anything. I ran a file across the critical edges, draw-file
fashion, to level and smooth them. It works fine.

I found, with the wooden prop off my Jodel, that it was out of
balance *chordwise*, not spanwise. The maker had drilled the center
hole off by about 3/32" and the bolt hole circle is radiused from
that, so the whole prop was/is orbiting the crank axis just a little.
My shelf-angle stand is tall enough that I can support a prop
vertically as well as horizontally to catch such imbalances.

Of course, we now have a Chadwick-Helmuth electronic balancer that
does the analysis with the engine running. Washers and small hardware
are attached at the specified place on the spinner backplate. Makes a
big difference. Saves instruments and radios.

Dan