what's the evidence that points to the Caliborn we see not being the same one that lived through the Masterpiece and became Lord English?

He sees himself being surprised by the Kids retcon-zapping into the Masterpiece, which he himself states is a bit weird given he’s literally seeing them zapping on the screen. Likewise, he’s surprised by ARquius’ appearance, even though he’s watched himself on the screen. He also has the Ring of Void, an item which our Caliborn doesn’t have.