I recently acquired a very well-made, hexagonal shaped drum key (as part of a parts lot from ebay). It is in mint condition; no rust or other signs of distress; it looks brand new! The overall design is "old school" and it strikes me as being nickel plated; the opening is slightly larger than a modern tension rod key would be. I don't know for sure which manufacturer might have produced this, though. There is no branding on it. Maybe Geisler/Beltone/Slingerland? 1920's? Common? Rare? Value range?

Your thoughts as to what this is? (photo attached)