"Every dimension of every piece is different and there are no holes in the box. (The 23 pieces have 69 different lengths, widths and heights.) 23 pieces is the smallest number for which this can be done. Articles about this puzzle appeared in Scientific American and the Journal of Recreational Mathematics in 1979.
John Devost's model has a 3-sided box and cover made from walnut. The top and bottom pieces are dovetailed to the sides for expansion/contraction. The pieces and slipfeathers are cherry. The box is large and heavy - it weighs about 10 pounds." -Bill Cutler