Wow this is an old thread. Here's the new link:
http://www.perryscanlon.com/files/solar ... tioner.pdf
And I updated the link above. As far as I know, nobody has tried to build it. A simple version would be easier to build, with just 2 pistons and a rod that connects them, and compressing air instead of a refrigerant. This would not be nearly as efficient, but with considerably fewer design issues.