I just found this on the GPLEA forum, posted by Dave Hughes. It should be of interest:
Yesterday I attended a historic moment at Silverstone.
F3 driver Andy Priaulx (www.andypriaulx.com) was asked by Lord Hesketh to drive James Hunt's 1975 Hesketh.
James won the Dutch GP in this car and led many others, including the last race at Silverstone where James crashed it! It was the last privately entered car with no commercial sponsorship to win a GP.
The car has now been restored and is going to be auctionned on Ebay.