Was the North Shore chip actually played at the casino? If so - my 2 cents worth, it would be an error. If the chip (which appears unused) merely came from the floor of the Shoddy Chip Mfg. Co., then, a test pressing or reject caught before shipment. I mention this because maybe your eBay seller has some further information as to how/when/where the chip was obtained. Wouldn't hurt to ask him! My guess, however, is seller knows nothing more about the item. In which case - well, enjoy your unusual chip.