Deborah was destoyed in the Battle of Cambrai in 1917, and only 2 of the 6 crew were killed (in fact 2 of them lived to a good age, although not long enough to see the tank found).
Apparently it had fallen partially into a shell-hole and as the Germans advanced, they buried it further so that it could be used for storage, and then as the war changed, the site was lost ... until about 20 years ago. So this is why it is is such "good" condition.
I was very impressd with the new museum ... very small, but really having so few exhibits that it's star could truly be seen. There was a video display about the battle, but other than that, there was Deborah -