From the book A Charmed Life by Marika Somogyi. She made these for some extra income on her kitchen table. She would make large batches of each and then sell them to art galleries and stores across the country. Obviously a costumer/prop master found them.
When Paramount mass produced knock off versions of the pins for Mork & Mindy merch (of which she saw no compensation), she took them to court (which they settled out of.)
Theoretically, there should be dozens of Hands and Moons out there.
It'd be fun to know if any of these others still exist.