NGC - This farfetched coin combining the designs of silver coinage from two countries is a good exercise in authentication.
NGC graders recently spotted a very interesting coin submitted for authentication and grading. The coin was submitted as a US Mint Error piece. However, it is clearly not a United States coin, because Mexico's "Cap and Rays" design from their 8 Reales coin appears on what we will consider to be the obverse. Yet when you flip it over, the design is the reverse of a US Trade dollar! How could this be?