Sure, George, happy to take a look. The effect (one of 5 in the book) is reprinted with permission from ABRA. A large golf score card is shown with room for 18 scores, nine for professsional golfers' scores, the other for nine celebrity golfers (Bing Crosby, Sean Connery, etc). Apparently this is what is known as a "Pro-Am" competition. The audience calls out scores for each of the golfers, with appropriate banter from the performer ("Bing bogies..." etc.) and he writes the scores on a smaller score card attached to the large board. An envelope is attached to the front of the board the entire time. Naturally, when the scores in the envelope are compared to the scores called out by the audience, they match. Seems like something that would be commercial and topical for the right kind of performer by updating the names (as Hofner himself suggests: Bing was dead already when this book was published!).
We have only two copies in stock at $7 each plus shipping. I note that the eBay sale is already at nearly that price plus shipping from the UK. This is a Supreme title, so out of print, though Magic Books by Post likely has reasonably priced copies in stock. Not sure if that qualifies as "rare" by eBay standards, as described in the listing, but we routinely see used titles sell there for more than the same new titles on our site, so I'll watch this auction with interest. Hope this helps!