Many years ago, Eric made about a dozen of these puzzles, one of my designs which was basically a Cutler Burr turned into a cube, with a few other mods. It's a level 10 puzzle with 6 pieces. Due to some problem with the wood, extensive sanding on the puzzles (like, hours) was required to make them actually fit together; I volunteered to do this task. I only got around to sanding the last two copies a month ago, and they fit together fairly well, but not perfectly; you can see small gaps in the photos. The two photos show all 6 sides of the puzzle (copy 2). The wood is untreated (walnut, I think); on older copies I had applied furniture wax to each of the pieces, but not these. The pieces, and solution, can be found here;
http://puzzlewillbeplayed.com/666/CubedBurrTJ/2/solution.html
The puzzle weighs a whopping 1 lb 5 oz., and is 3.5" wide.