I've got a couple long spout oil cans (Santa Fe and Monon), a couple kero lanterns (Santa Fe & NYC), a couple "tallow pots" (D&RGW and UP) a Hamilton 992 pocket watch, and several builder's plates. My bell is one of my favorite items, from a Baldwin NP 0-6-0:
I sort of specialize in railroad items from the Disneyland Railroad. Here's a pretty complete collection of all the various builder's plates on the engines and equipment (some original, some poured from the same patterns that the real engines got their plates from, and some repro), along with a selection of tickets:
I even have a hand-striped and numbered section of one of the engine's tenders:
Additionally, I have about 50 textbooks on railroading (not the general interest kind you find in bookstores--these are catechisms and correspondence school textbooks from the 1890s through the 1940s), along with loads of photos and blueprints.