On the Primitive Archer website there is a "War Bow" thread. Some of the best war bow builders in the world frequent and participate in this thread. Most of the war bow "experts" are from Europe but there are a few from the US and Canada also..and elsewhere.
Not only do they discuss building war bows but also how to get yourself in shape to be able to draw a heavy draw bow and the best techniques for drawing heavy bows but also the proper dimensions of an authentic war bow.
Also, Google "The Mary Rose Trust". This site is dedicated to the research of the bows and arrows that were recovered from the Mary Rose, a ship that sunk in a river in England hundreds of years ago. Because of the anaerobic conditions in the mucky river bottom, many of these bows and arrows were preserved and a few preserved enough to be strung and shot, I believe.