2023 Niue Scooby Doo The Mystery Machine 1oz Silver Colorized Proof Coin. 2023 Niue Scooby-Doo “The Mystery Machine” 1oz Silver Colorized Proof Coin. A limited-edition collectible minted by the. It features a unique van-shaped design with vibrant colorization on the reverse side depicting the entire Mystery Inc. 1 Troy ounce of. Approximately 53 mm x 36 mm. Proof quality with a colorized reverse and a frosted/mirror-finish obverse.