I have a Baldwinn Locomotive Works July 33938 1912 "Philadelphia U.S.A." , made by Bachmann -
Train that I am trying to find information on.

It belonged to my late Uncle Bob, I know nothing about the train, need help with how do you know the size of the guage, and how do I price the train for selling it, my Uncle had 12 locomotives with about 27 cars and 5 bosuses (sorry if I spelled that wrong)

Help please

Tim