Great book, Bill! I just got it in the mail yesterday and have been reading it nonstop.
You mentioned that in going from the Allison-powered P-51s to the P-51B the wing was moved slightly down and forward. Is there some discussion of the actual measurements in some other thread here? On page 250 the side-view comparisons seem to indicate that the wing was moved downwards 3" relative to the fuselage but it doesn't call out any forward movement. It also seems to show the tail being raised by 2" relative to the FRL. Was the P-51B tail really taller?
The P-51D Airplane Assembly drawing, 106-00002, lists drawing 73-20001 for the empennage installation. That implies to me that the P-51D was still using the same tail as the early NA-73 Mustangs, which is what I expected to see. But the side views seem to show the tail height relative to FRL increasing from 67-9/16" to 69-9/16" when going to the P-51B.