I'm sure you know Mike, but just to clarify for those that don't know the whole history of #s 80 and 81:
In 1920 #s 19 and 20 were custom designed and built by Alco for SVRy. Then in the early '40s they were moved to Alaska and became YP&Y #s 80 and 81 respectively. In the mid 70's they came home and are once again SVRy #s 19 (operating) and 20 (slated for rebuild).
#20's tires are badly worn. The story goes that she was used to push a rotary in her final years of operation at YP, and the crews used lots of sand while doing so thus wearing the tires.
dan