I was the first in the UK to build one of those. As far as I know, you can still buy the plans on a download form James Robinson.
I find the bike poor at cornering. It's fine on the open road, and on a velodrome, but not good around town. It's not the easiest recumbent to ride, and one builder I know found his almost unrideable (he has riden mine though).
I did a webpage on mine several years ago:
Clicky 
