I first prepared the pieces, with the help of a scalpel to get the most clean cut possible. Then I glued the stack, easy task.
The playability is correct, according you have opened a bit more the air entrance on the whistle stack, and that you seriously pinch the nose hood in order to lessen the air leaks. And the sound is very decent! Yet soft, but a nice woody colour
The great UkeVal / LuthVal made one too, and did this cool video:
The book Paper Music seems to be out of stock in English, French and Italian, but I found my english sample on Amazon, used (but complete) for €2.99.
The german version, Papier Musik, is still available new at Dan Moi, for €18.50. You can get it here : http://www.danmoi.com/musical-instruments-papercraft.html