The machines are available from Lehman's Hardware store out of Kidron, Ohio.
http://www.lehmans.com If you don't have one of their catalogues you owe it to yourself to order one for winter time entertainment if not for purchases.
THey even have a homesteading forum site at
http://www.countrylife.net as well as sponsoring some others
http://gaelio.com/homesteadfriends/board.html
On this last one there is even my mug shot when I used to post as greenbeanman.
Did you ever think about converting a cement mixer into a washing machine?
It would be a front loader kind of like one of those Staber brand machines, except wouldn't spin out the water nor have a wringer. A wringer would have to be purchased seperately. The mixer could easily be powered by small gasoline engine or electric, or maybe even by a Savonius rotor powered by wind.
http://www.ata.org.au/articles/70byosav.htm
If you should convert a mixer, you will need to remove the mixing paddles and install some that are less agressive. The bigger the mixer capacity, the bigger the load capacity.
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Oops, I just reread your post and you asked about a USED machine. I'd still try Lehman's as they are very knowledgable folk and always willing to accomodate as best they can.