I'm intrigued by the reference to the Essex Aero Sprite. I'd never seen a mention of it and Google doesn't come up with anything. Are there any pictures to be had? I wonder why the 40's engineers went for magnesium. There was another a/c called the Planet Satellite that was mainly magnesium, I believe, and that didn't progress either. Essex also seems to be an unlucky county for light aircraft designs as I rememeber seeing a thing called the Tawney Owl at Stapleford years ago. It was a low-wing pusher with twin booms and it apparently failed to get airborne on it's maiden flight. Heard a rumour that it was being considered for a re-engine and a re-build. Any truth in that?