Muhammad Ali Autographed Memorabilia. Check out this Muhammad Ali Autographed Sports Illustrated Magazine Gem Mint 10 - PSA/DNA Certified. This is a Sports Illustrated Magazine that has been hand signed by Muhammad Ali. The signature was graded a Gem Mint 10 by PSA. It has been certified authentic by PSA/DNA and comes with their sticker and matching full page certificate of authenticity. SportsCollectibles.com offers a wide selection of MLB collectibles. Product ships within 1-3 business days and ships free if your order is over $100. Buy with confidence as this Muhammad Ali autograph has been authenticated.