Randolph Forgot to mention this in my last post:
In the early 1990s (in fact I think it was 1990), I was the proud owner of a puzzle created by Erno Rubik, called Rubik's Magic Puzzle. It was black with three separate rainbow-coloured rings, which you would move about to form three interlocking rings.
The only one I can find online is on www.rubiks.com (see related link), but shipping is twice as much as the item itself, and the new one is an ugly colour.
If anyone knows where I can get one of the original ones, for a reasonable price, please let me know.