So this cylinder was in my grandfather's gun safe, and I acquired it after he died almost a decade ago. I know nothing about it, I have reached out to multiple people over the years and never gotten a response back. I can't imagine him keeping something completely worthless locked up (he had a whole shop with guns/parts laying around), but I have no way of knowing if it has any value whatsoever. All of the Dragoon cylinders I can find, even with matching carvings, don't carry the blank "Patent N" marking.