I was lucky enough to be the high bidder recently on a Gem roller organ
with 13 cobs in reasonably good condition.  ($375, for those of you who
keep track of current prices on mechanical music items.)  While I
realize from my post-purchase reading in the MMD archives, eBay and
other sources that these are fairly common due to the large number
produced, this is my first personal contact with one of these machines
that was not in a museum.

I have some minor repairs that need to be performed and am looking for
some guidance.  The first is that the rectangular pin on the shaft that
is supposed to engage with the end-of-song lever is sheared off.  What
are the correct dimensions for this pin, and how do I remove the old
one?

I can't tell from what is left whether the old one is peened over or
welded in place.  I would like to get the old one out without doing any
further damage to the machine.  At some point, I would also like to
replace the worm gear, since the original was damaged due to the
missing pin.  Does anyone out there have spare parts for sale?

The second question is more general.  A few of the pins on each cob are
either missing or loose.  Is there a preferred method for tightening
the pins that have been pushed over so that they are now in a slot
rather than a hole?

It would appear that these loose pins have been pushed in the direction
of the grain in the cob's wood, which spread the fibers and left a
slot.  I could imagine making up small quantities of epoxy to fill in
the enlarged hole, but this would leave an obvious mark on the surface.
Is there a better method that wouldn't leave a visible scar?

I want to take this opportunity to thank the editors of the MMD for
setting up the MMD Archives.  I was able to answer many of the
questions I had about the Gem by looking in the old digests.  This
saved everyone else from having to rehash old subjects, and gave me a
lot of information quickly following my new acquisition while the
excitement was still fresh.

Jack Breen
Southboro, MA