I've never really collected Railroadiana items. My dad's best friend and our next door neighbor while growing up worked for Southern Pacific for 42 years. His name is Elmer Wright. At one time he was the Yard Master for the SP Bayshore Yard in San Francisco. He is now in his 80's. He just recently gave me the following personal SP items:
Brass Switch Keys
Lantern
Railroad Watch Certification Card
SP Rules and Regs Manual
Safe Work Practices Manual
SP Gear Bag - Given out as a safety award
Switch Man ID Card
Yard Master ID Card
They're all on display in my layout room.
Matt