Add the Greatest of All Time to your Worldwide Stamp Collection while supplies last. This 2017 Souvenir Stamp Sheet from Grenada celebrates the 75th Birthday of Muhammad Ali. The $12 Commemorative Stamp shows Muhammad Ali ready to rumble. Muhammad Ali retired from Professional Boxing in 1981 with a record of 56-5 with a stunning 37 Knockout Victories. He was also an Olympic Gold Medalist at the age of 18, competing at the 1960 Summer Olympics in Rome. This product is in Mint, Never Hinged condition.