I started designing puzzles in 1982. That was roughly the same puzzle, but without the 2 cylinder obstacles. The task of this puzzle: remove the ring in the center. I sold 40 of them. 3 collectors sent me the solution. Warning: it is a tricky puzzle!!
12 pieces with inlaid letters. Pieces with tongue and groove. All pieces 20x20 mmSlide from the starting position ALBWHITE CK!!ET TO !WHITE !BLACK! On the back there is a slide up and down. This slide changes the free hole.Then slide to BLACK! WHITE! easy?Material Acrylic.