In the late 1860s there was a shortage of currency in Texas. Instead of money, the Galveston Harrisburg & San Antonio Railroad construction workers were issued tokens made of gutta percha. These could be used to buy food and other assundries The merchants along the construction route could then redeem them from the railroad. The Sunset Route logo was in use way before the Southen Pacific gained control of the GH&SA. It was not long after that the SP adopted and modified it.
My favorite artifact is the Mondaine Official Swiss Railroad Clock. First noticed it on top of the Jungfrau Station in Switzerland. Love the clock face so bought the wall version (hangs in my office) and wristwatch before leaving Zurich.