2 of the holes are threaded in the hub half of the hole, and push the
bushing into the tapered bore of the hub. They are probably at 180 degrees
to each other. The other hole is threaded
in the bushing, and pushes the bushing out of the tapered bore of the hub
when tightened.
Take out the two "tighten" screws, put one of them in the "loosen" hole, and
remove the bushing. This is a fairly common style of taper lock bushing. I
probably see more flanged
style bushings, but not by much.

"Proctologically Violated©®" wrote in message
...
You might be right--one of the holes in fact did *not* have a set screw in
it!!
Now, if I can only figger out which one it was--they all look alike now!!
That third hole (w/o the set screw) similarly straddled the bushing and
the hub, and it looked threaded into both. I'll check it again.
--