This picture is from a 1997 Two Cylinder Magazine.  John Deere made cut-away tractors to illustrate the inside of a tractor and how it operated.  They had an electric motor which plugged into a 110V outlet, so the tractor would turn, and you could watch the pistons, valves, and crankshaft turning.  Deere also made cut-aways for the 4010 Diesel, also, which they would display at the MN State Fair.  I was told that the largest 5 JD Branches, each had one, and they would have a man travel to JD dealers, for an afternoon meeting with farmers.  It took a lot of work to make a cut-away and I am not sure what happened to them in later years.

(70 Tractor 003 (full).jpg)

70 Tractor 003 (full).jpg (77KB - 98 downloads)