Over 25 years ago, I purchased an autograph book from Tracks UK full of great sigs from the late 70's-early 80's, classic rock like The Who, Meat Loaf, punk rock like The Clash and Ramones, etc. Among them is this Black Sabbath with Ozzy and Dio! I know Dio replaced Ozzy, but I did not think they ever appeared together. The adjoining page has drummer Bill Ward.  The back pages have a fully signed Nazareth and Mike Ofeild. Are there any Metal experts that can help?