I also went to this great event, as a crewmember with the Crompton Military Vehicle Collection. The CMVC displayed a Hetzer (an original 1944 SdKfz.138/2, not a G13), SdKfz.250 'neue', SdKfz.251/D, SdKfz.7 (cargo) 8-ton and a Schwimmwagen. In all around 30 vehicles attended, and most were available to take passengers around the track for a small fee. Lots of people used this opportunity, and there are many pictures and vids posted on the internet (like here: http://www.youtube.com/results?search_query=militracks&aq=f)
The track in the museum park was about 1 mile in lenght and completely unpaved, with even some more serious off-road bits. Getting the Hetzer around without too much damage to the trees was quite a job, so we put the Schwimmwagen in front with someone on the back to guide the Hetzer's driver on each round.
It was a busy weekend with 4800 visitors and great weather. I also drove a lot in the vehicles. Time will tell, but there is a good chance this event will be organized again next year, around the same time.
My own pictures of this event:
Greetz
David
PS I am in the last picture posted by Joris, as the Hetzer commander with the khaki cap.
