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Gary you wrote:  I have one of those and it does NOT glow in the dark

My question was meant to be part humorous and part serious.  Did you look at the photos of the one in the eBay link?  That one certainly does appear to glow in the dark.  We’ve all seen plastic stars etc, etc, which do glow in the dark, and we’ve all had hand bearing compasses with beta lights, which work well when first bought, but lose their strength over time.  See https://science.howstuffworks.com/innovation/science-questions/question388.htm and https://en.wikipedia.org/wiki/Tritium_radioluminescence , so it’s not impossible.  My worry is that whilst modern photoluminescent plastics appear to be safe so long as you don’t  come into serious contact with them, should one be cautious of this particular application bearing in mind its age, unknown providence, and the fact that you use your fingers to move the plastic disc.  Then maybe you lick your fingers to rub the pencil marks out. DaveP