I have been searching for a month for a tornado coin op for my neighbor. This grey marble was just posted 3 hours ago:
http://washingtondc.craigslist.org/doc/for/4638584443.html It looks to be in excellent condition. The asking price is $600. It is a bit far for me to drive, so I must pass. Could this one have Merkle rods? Good luck to any who wish to pursue...