When in doubt, here's the book of books! http://www.amazon.com/Cartridges-World-11th-Frank-Barnes/dp/0896892972
I grew up in a sporting goods store in Kansas City, MO. Up until a couple of years ago, I was doing much more reloading, varmint hunting, and plinking as I was detecting. Although I never collected old ammo, I know a lot of folks who do. A .54 cal. rim fire is a rare cartridge, but really not worth very much. Perhaps a buck or two to a real collector, based on the condition. Since it is at least 90 years old, that's all it is good for. However..... The one thing to remember about old cartridges, you cannot rely on them being 100% inert. While they might not have the power they once did, they can still maim! So treat them with the same respect they used to have, when they were loaded into a firearm pointed at you!
Alan Applegate