Around 5 years ago I was in Montana picking up a Dodge WC12 from a friend who gave me Hayes Otoupalik's phone number as a possible source for parts. Mr. Otoupalik turned out to be a very nice gentleman who later sent me a free copy of a video he produced about his Model 1917 Six Ton Tank. In the video he personally gives a complete "walk around" of the features and operation of his tank, and even uses it in a mock WW1 battle at the end. If you are interested in these tanks, you will want a copy. The last time I wrote him he could be reached at
this address.