The Lorry driving the Saw at Robs Logs was a Ford Thames with a Petrol V8 Engine, the logs must have been very expensive.
More of the display can be seen amongst my photos here,
http://www.tractiontalkforum.com/showthread.php?t=28409
I thought that the Charcoal burning GMC. was interesting, it was claimed to have been in use for 25 Years .