Maran — welcome to the GMB.
Fascinating set of objects. Why just even numbers from 20 – 40?
I first tried to find a games discussion board, but they seem to be dominated by computer games. Worth trying — you might have better luck than me.
Failing that try the Opie's museum (somewhere near Bristol, I think) and ask them how to progress your query.
Anyway today I was in the thunderbox reading Professor Ian Stewart on Egyptian Fractions (don't ask, but fascinating), and put the book down when there was hammering on the door "Are you reading in there?". ... and "You know we've got to go to IKEA". When I picked it up again it fell open at "Tippe Top Twisters" and a picture of something like your objects. Do a search. Do your objects behave like that?
Good luck and please let me know if you find a traditional games discussion board.
And, unfortunately, I didn't get out of going to IKEA, despite having a headache and a broken leg!

Bernard C.
