Thanks for the picture, Fritz.
When I built my On3 Durango Tower last year, this picture from the Sundance calander was very useful to me.
It shows the horizontal braces under the floor of the coal bin, the supports of the operators platform beside the chute, and the angle of the chute itself. One of the other oddities of the Durango tower is the large sheet iron which both kept coal from falling onto the operators platform, and also helped reinforce it. It shows clearly in this picture, and is often mistaken for shadows, or something behind the structure.