Yeah, here's my old Tornado Nylon prop (9x4.7), and I had a yellow prop as well (for a Cox Babe Bee)!

Just kidding. Great article with catching enthusiasm. The flight speeds mentioned are a bit too enthusiastic, though. A 7" pitch prop at 16000 rpm has no thrust yet at 105 mph. The 12x12 prop on a long-stroke should give around 100 mph, and a 1960s pattern ship flew around 60 mph. Doesn't derogate the article, though.