The Frisco 1522 is not owned by St. Louis. It is owned by the National Museum of Transport in Kirkwood, MO.
The St. Louis Steam Train Association, which restored the 1522 found that the problems that they had with the 1522's lead truck and other things were problems that no amount of tweaking and adjusting could fix. They even went from friction to roller bearings on the offending pilot truck and still had problems. From what I understand they found that it was just easier all around to park her back at the Museum than to keep hitting their heads against a brick wall. (and much less painful). Nothing against the guys that did the repairs, they were professional in every sense of the word and very transparent in their operations. If something went wrong, they cancelled the trip, no if's ands or buts. I think that it got to the point where the mechanical problems were cancelling more trips than they were making.
There are other Mountains on display, the one that I saw in Rolla, MO comes to mind immediately.
Rick Steele