The photo was taken at the 2008 10th international Aikido congress, where there was also an exhibition in Tanabe with relics and photo's of O Sensei's life. Most of what was shown came from the Kumano Juku Dojo. This bokken was unusual big and heavy, more like a suburito.
What is the specific detail that you are looking for?
according this pic, which David have in his collection HERE
and if is really same bokken then it look almost like suburito, so it seams that I need to make another one : )