I found this View-master set at a sale recently. I never really watched Bonanza, it was a little before my time, but I collect View-master slides so it seemed like a good addition.
"That Girl" Marlo Thomas guest starred as a Chinese(!) girl sold into marriage to Hoss.
Courtesy of www.ilxor.com
Doing a little research on it, I came across a bit of trivia that sounds like an urban legend, but looking at the first slide in the set, I think it's legitimate. It's said that as a gag, the actors decided to all give "the finger" to the photographer thinking he would catch it and remove it from the set during editing.
Apparently, he didn't notice and it went to production. Looking at the picture below, it does seem beyond coincidence that they all have their hand in their pockets in that fashion. That's not a very natural pose. The legend goes on that Sawyer (maker of View-master) attempted to recall the set, but too many had gone out. A second set was issued without the offending slide.
Just in case you forget how to use a View-master, they included instructions.