Hello Ed,
Well, let us not start that most puzzling theme in this thread
It once has been discussed what could have happened. Two options: 1) the original documents (if not deliberately destroyed) have been lost when they were still in German hands or 2) they were lost when in Allied posession.
Never give up any hope, after all the wooden panels with all victories of NJG 1 have been found in a German barn years ago...
Best regards, Marcel