Stewart Coffin, author and famous polyhedral puzzle designer, welcomes the replication of his designs, many of which are not under patent. He writes:
It is not necessary to ask my permission to manufacture and sell any of the designs listed here. I encourage others to become involved in this rewarding and fascinating craft. Unless otherwise indicated, all of these designs are my own creations. Yet you might say that is only partly true, for they are all based on ideas that have evolved over centuries, their origins fading away into the dim and distant past. As far as I am concerned, they can all be regarded as in the public domain.
Link to this and autobiography here.
Stewart Coffin, "Cetus" Skor-Mor Corp, 1970's
Stewart Coffin, "Tauri",Skor-Mor Corp, 1970'sOther puzzles of interest:
"Ring a-Ling" Designer unknown, Skor-Mor Corp 1970's.
Mike Reilly, "Weaver's Puzzle"
