>It has worn wheels.

No, it doesn't; the wheels actually have very little wear at all. What happened was that the Key turned the treads so it could operate on streetcar trackage, which has made the flanges almost non-existent for ARA-style trackwork. It tends to climb switch points, and because of the odd-ball back to back distance, guard rails can't really reliably keep it from climbing frog points. Besides, it has spoke wheels with tires.

RVJ has the following tread contours to contend with: AAR (two kinds), Key-compromise (Key units), Key-streetcar (different than SF), SF Muni (LRVs etc used the former Muni standard for the Iron Monsters), and Blackpool Corp Transit. If you include the 1043, add TRS/SDERy streetcar tread. It's quite a trick to get them all to function on ARA trackage and specialwork without derailments. It also takes a close eye on track maintenance.