Badboy,
So far you have explained following:
"The fact is that changes in the various coefficients are somewhat masked when the large number of parameters involved are all merged together numerically to produce the curves. I know this because the effects described in those reports have been included in my analysis and only appear to make a negligible difference to the EM curves for prop fighters, and in practice the reduction in the coefficient of lift due to compressible flow appear to be masked, to some extent, by other effects that increase the coefficient of lift, such as the contributions to lift from thrust and propwash, so that although those things have been modelled, they aren’t at all obvious on that type of diagram."
Well, some effects might be masked but this Clmax difference can be clearly seen from the real world test data which certainly contain all masking effects. In the case of the P-51 clmax difference if compared to other fighters is far more than "negligible". In practice at 30k the P-51 could pull more than 1g more instantaneous at high speed than competion. At sealevel difference is small but as can be seen from the NACA data, the difference exists there too. Basicly by limiting your analysis to sealevel you miss one of the main points which made the P-51 so succesfull.
You should also study very carefully that NACA 1719, specially graphs which explains when buffeting starts. You can also compare it to other real world data.
gripen
