Be careful on this one. Over a year ago I bought a used Limbo that had a bad shock, thinking I might just "fix" it like this. In the process of my research, I found tales from owners who tried that and busted the frame mounts for the shocks. Apparently the stress of a fixed link at that point surpass the frame's engineering. I ended up installing a better quality shock. Finding the ride shock was a education in itself, learning about leverage ratio, damping rates, etc. And after all that, I still ended up selling it because the seat height was just a little beyond what I could live with...I'm a short feller.
I will say that Burley made some very fine recumbents, and you can often find them at about the price this one is selling for. You have to diddle a bit to get the seat angle just right, then ride your heart out! (I got a Burley Canto after I sold the Limbo.)