Autographed Kansas City Royals Harmon Killebrew baseball. This item comes with a Certificate of Authenticity (COA) from Mounted Memories and includes their matching holograms. Mounted Memories is the largest signing company in the country and Dan Marino serves on their Board of Directors. Our products are fully licensed by the NFL, MLB, NHL and the NBA. Add a custom display case or frame for your valued collectible. Compare our prices and quality and save. Incentive program managers, please visit our section for corporate sales.