"Chuck" wrote: (clip) you could make a metal plate with the same sized
center hole as the spindle, with indexing holes drilled therein, (clip)
^^^^^^^^^^^^^
The difficulty here is laying out and drilling all the holes, making sure
they are equally spaced. Another possibility would be to mount a circular
saw blade on the spindle, and use the notches between the teeth. Problem
there is enlarging the center hole to fit your spindle, and making sure it
is perfectly centered.

Maybe you could clamp a saw blade to a piece of metal or plastic, and use it
as a drill guide.

BTW, I just bought a Veritas Optical Center Punch from Lee Valley. It
would be invaluable for such a project--you get to position the center punch
using a built-in 8x magnifier with cross hairs.