You're assuming an awful lot. I saw Jon Stetson do linking finger rings with no stooging whatsoever, just clever stagecraft. Paul Gertner got a ring on an hourglass. He's been doing it since the 70's in fact. You can find it in his book Silver and Steel. As Christopher pointed out, this is easy to attribute to copyright law. Now let me ask you a question: why did you think the cover was blurred out? And it never occurred to you that it was just two people a little anxious about being on camera? Watch a documentary sometime. Pardon me if I'm skeptical.