Two things I think may be wrong with your post....
First, the engine was 452.
Second. If the engine was coming from Mears towards Poncha, than it did not turn around. The hill it was sitting on was about 1 mile from Poncha Jct, and the engine was facing this direction. I would imagine the engine did roll more than once, finally landing on the engineer's side. It is impressive, the distance from the grade to where the engine rested. I would guess around 30 to 40 feet vertical from the rails to the engine!!! I think the original picture looses some of its perspective, probably because the photo was taken pointed slightly upwards...
There was another 1903 wreck on Marshall Pass, I believe much closer to the pass itself. Could this be the wreck where the engine turned around??
Casey