RPGMemes

Twist: You think this is the legendary lost crown of Foo? Some rotten trash you grabbed in a dungeon just happens to be the thing you've been looking for all this time? Pull the other one! It's been so ravaged by time that none of the markings or engravings are clearly visible. Best you can hope for is that some merchant will buy it off you for scrap.

Even if the PCs think this is the lost crown of Foo, only the kingdom's last grandmaster artificer can conduct a conclusive test. Assuming you even find them, it's not like they take appointments from any dirty old adventurers off the street.