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.
Exchange PUZZLES with PUZZLES. The center piece can only slide up and down. Pieces cannot fall out through the transparent top plate. More assignments on the back of the puzzle. Material MDF.The letters are covered with transparent foil. You can slide without damage.