Very slightly adapted from Travis77's fine original design, simply to add depth and export the parts as .stl.

These should print just fine on a makerbot, but make sure to check the size first as I haven't had a chance to. The depth of the pieces is very slightly less than the exact fit (1.27mm) to allow for printing error and ease of fit.

Thanks to Travis77 for this great classic puzzle and the Sketchup source file!

Print. Cut off. Assemble.