I know it isn't Frisco, but I figured its steam train related and maybe and of our many railroad history buffs would know anything about where it came from/possible backstory. Looks like it says 1880/84 on one side of it. http://i.imgur.com/gyLvrkQ.jpg http://i.imgur.com/NnOsqoR.jpg http://i.imgur.com/qY6BHhk.jpg Frisco152251
That looks like a old one. Can't tell how big it is, but that type used to be in the engine compartment along with the spare air hoses. The crew would use them to change broken air hoses. That type generally didn't walk off.
That is an old time monkey wrench, or at least that's what they used to be called back when I worked as a mechanic when I first went into the workforce back in the 60's.