I have some Marconi images of the Heli-Tele TI aircraft...... the black and white ones are the 'final' version with the left seat reversed but the earlier colour ones had the seat facing forward with a rather complex control arm.
https://dl.dropboxusercontent.com/u/10932568/img644.jpg
https://dl.dropboxusercontent.com/u/10932568/img645.jpg
https://dl.dropboxusercontent.com/u/10932568/img646.jpg
and the older one....
https://dl.dropboxusercontent.com/u/10932568/img647.jpg