Goog luck ! The more tricky puzzle I have seen !
Take red-wood for more solidity and esthetic !
Pilou 
Ps If you construct it : Take this section 226 unit for the initial rectangle of each piecces !
I have something like this. Only you have to put the blocks together to get a cube.
A cross is more architectured 
Another famous Puzzle ! Thanks Cameyo
is Soma : a danish Tangram
http://www.fam-bundgaard.dk/SOMA/SOMA.HTM
Have fun
Pilou
Ps and some Polyominoes http://www.ics.uci.edu/~eppstein/junkyard/polyomino.html
Pss
And a great site ! a Must : Whet your plane http://www.johnrausch.com/PuzzlingWorld/default.htm
A wooden mirror ! Astonished !
I want the same for my computer !
All the morning a little polish for a better Zbrush visibility and at the automn a little pile of browny leaves to pick up
I love it !
Pilou