Hot is correct. My Mountain is a one-of-a-kind, and actually my first real attempt at creating an O Scale locomotive. Coal in tender, not much in the way of detail anywhere, and in fact not O gauge, but 1 1/8" gauge, so that the locomotive itself better fits the track gauge. Its genesis is an All Nation Mountain sand cast boiler. The tender is a wood block.
In my opinion, a truly scale model ought not to have huge flanges on the outer drivers, contrasted with no flanges on the rest. That is just an opinion, and obviously some find such flanges add to, rather than detract from, a fine scale model.
Here is my dirtbag Mountain. I have done better since - once in a while a lot better:
