I agree with you that a serial number is not a cancellation. There are many Nevada chips that are only known in notched, drilled, or damaged condition. In most cases, these are chips which are unique or close to it. However, there are exceptions. The best one I can think of is the Las Vegas Club $5 C&J (11th issue). This is the chip that has a great picture of the one-armed bandit slot machine. This is the same inlay as the famous Arodie. Close to a box exists of this chip - all of which are cancelled with an ugly, black zigzag pattern. If anyone knows of one that is uncancelled, please inform me!