Stability and Control characteristics of the Early Mark Spitfires

[Crumpp]

If you want to sell instability to me, or anyone else who's got a good understanding of the matter, you'll need to explain how both of the above gradients can be positive in an unstable aircraft and how it was possible to fly the smooth stick fixed turns as shown in figures 17 and 18.

or anyone else who's got a good understanding of the matter,

Your good understanding? Is that with the long period oscillation's your claimed, the slopes of the curves, the difference between stick fixed, stick free, dynamic and static?? I am confused as to where your good understanding is demonstrated.