There are fairly brilliant ideas for a panic fighter posted. Using the rules I will see what I can dream up. I have use of the Reno air race, 2018 edition, data which should include some diagrams perhaps of a P51. I build a small model of the P51, wind tunnel test the model, then using both NACA data plus the 2018 Reno air race data to confirm the design. Due to a limited industrial capacity, we build the airframe out of plywood, like the Mossie. The engine is a RR Kestrel and the armament is 4 .50 mg, 2 in each wing. Improvements could be fuel injection, Water-methenol injection and higher octane fuel. Due to mostly grass runways wide landing gear is preferred. The last shortlist I saw, from riggerbob, included North American Aviation and that with the Reno air race data, 2018 version, leads me to believe that a P51 is plausible. The Kestrel should be no problem since the British sold several of them to the Germans to test their ME 109.