£495 per hour!!!

I would hope that you get a break on that rate if you sign up for a full conversion course. The website doesn't provide many details, but it does say:
A full conversion course is available, which covers all system and safety procedures and aerobatic parameters.
Perhaps a stepping stone to other warbirds, or a delight to fly in its own right. Available to rent for solo flying, subject to certain conditions. Ring for details.
Chippik, please check your PMs.
Waldo, I have also sent you a PM. To whet your appetite, here more information on the CHAA (an article entitled
'The Yellow Horde' of Harvards still going strong). Unfortunately, the video clip is no longer available, but there are some photos. See you at Tillsonburg!