Harry, enjoyable read concerning full scale. Not sure I'm going to agree about an aileron not being able to create a stall. Try using barn door ailerons as flaps and see what happens. As far as your comments about 3D models being able to keep the roll rate active past stall really has nothing to do with proving your point. The main reason a 3D type airplane can continue to roll is because of the prop blast moving across the ailerons. If you have ever seen an airplane doing rolling harriers and experience an engine failure you will see the roll stop immediately. I have seen some extreme 3D type electrics sitting in a stationary hover and alternate roll directions.
I am somewhat jealous as I would love to take a ride in a P-51. IMO if you can pilot one of those you have my respect as I know it is an airplane that has no forgiveness. All the model P-51's that I have flown have had very bad control cross couple. When rudder is applied the airplane has wanted to roll the same direction and pitch downward. Is the full scale P-51 the same?