Ok let's not go down the rabbit hole again.
You are using a weight and balance sheet that incorporates the longitudinal stability fix and is from February 1944 to prove the NACA conclusion was not correct.
Yes, the RAE addressed the issue of the longitudinal instability in the Spitfire around 1942. However, the
Spitfires used in the Battle of Britain did not benefit from the fix.
This is Spitfire K-9787 and was tested in
June, 1939.
http://www.spitfireperformance.com/k9787-fuel.html
If you click on the center of gravity link at the bottom of the page...
The weight and balance diagram is K-9788, the very next Spitfire off the production line.
http://www.spitfireperformance.com/k...cg-diagram.jpg
We can eliminate the February 1944 document from the thread as not applicable and conclude it is the result of the NACA findings.
Which brings us back too:
MAC as measured by RAE:
19.5+8.4 = 27.9/84 = 33.2%
NACA CG as flown = 31.4% MAC
The NACA flew the Spitfire with the CG 1.8% MAC FORWARD of the aft CG limit as defined by Supermarine.