I found the articles interesting because the vehicle mentioned is not either the "casey Jones" or one of the two Mack cars described by Dr Sloan in "Silver San Juan" as being built in 1905.
I also was suprised that they ran it on the D&RG to get to Silverton as opposed to putting it on a flat car for the trip. Over the Third division and RGS perhaps? or else Poncha, Cumbres, and Chama.
I had missed, or perhps forgotten about the photo of the Stover in Dr Sloans book.
A quick Google of the Stover Company revealed that they manufactured windmills and hit and miss kerosene and gasoline engines untill about 1940.
Evidently if you are into collecting items of this kind, they are the Mason Bogies.