Ed Copeland,  Roller Organs are wonderful machines, very common, the
Gem being the most common model.  For a price comparison, the last time
I checked Nelson Pease was selling rebuilt Gems (new bellows, replaced
pads, etc.) for $575.  You should be able to find the rollers (cobs)
for $10 to $20 each.  (But I've seen them recently on eBay Internet
auction selling for over $25).

The repair work you mention is not difficult, but figure some supplies
and time.  Make them a lower offer :-)

If you'd like additional info, just visit my web site (mentioned earlier
in MMD) at:

     http://www.bright.net/~allmax/index.htm

Todd Augsburger