I bought one from the guy in FL off of ebay also and it is a very well thought out test stand. I've had .049 though the Super Tigre G4500 on mine.
Here was mine when I got it in the mail.
However now that I have more wood working tools it's easer for me to cut out a custom mount for a engine out of scrap, use it one time and trash it rather than try to clean all the oil off the nice test stand.
The tracks you can get at wood working shops. We use them in wood working to make jigs, slides, fence, and work piece holders for saws.
http://www.woodcraft.com/product/200...r-channel.aspx