I don't think they do.  I was

I don't think they do.  I was luck enough to be there on a Saturday the club was operating and was  if I wanted to try it. They let me run a UP passenger train.   Joe

PSMRE

If I am correct, part of their charter and obligation as a museum layout is the faithful depiction of Washington history in the 1950s on the layout. I'm sure during their operating sessions as a club they can and probably do at times run other equipment. But during museum hours I have never seen anything but the native railroads running and represented. I will check with several modelers who are PSMRE members at the local Tacoma Clinic of the NMRA to verify.