Think the Bessoneau is used by the Kestrel Gliding Club, which has photos of it on their website. I am sure that it is not original to Odiham but it seems to be the last one in the world.
As for Duxford, they won't be interested in anything like this - it might cost them money and they don't have any of that (judging by the ticket prices for the air show next month!!). Duxford is only interested in the multi-million creations of Sir Norman Foster.