This museum and collection, which was featured in the TM Books & Video DVD "Tinplate Legends in Action 3," is usually only open to the public two days a year, and this year, those days are Friday December 6 and Saturday December 7. See THIS WEB PAGE for more info on hours and admission.
I have been to see this collection twice and can't recommend it enough (and the DVD, too). Also, this museum is very close to the Carnegie Science Center (home of the Miniature Railroad & Village), so it can easily be visited the same day(s) with just a little planning. And for those really looking for even more train action on Saturday could then head off to Kennywood Park and see my club's layout and ride the park's train, weather permitting (buying tickets online is advised for this, as KW charges more at the gate).
Andy