I did but they didnt make the turn cracked into the wall a the boiler exploded!!! I dont believe anyone has ever made one, it would likely require a 30" radius turn. The FEF's require a 22" min radius and the 4-10-2 requires only a 20" (smaller drivers).
Ouch!!!! I found a clip online of how the UP 9000's sound with their third cylinders... Unique, and unforgettable!
If there is a 4-12-2 in Cheyenne, I don't know where they could hide it. There is a 2-10-2 in the roundhouse, #5511. Last time it ran was fueled by burning tires for filming 'Last of the Giants'. It sits idle in Cheyenne, too rigid for the mainline. The 844 has trouble with some switches, and is restricted from many wyes and yards due to its wheelbase as it is.