The MB2 used the air cooled Dagger engine (wiki says an air-cooled engine was used for for hot climates).I an going to have to do a bit of a rewrite, as I just looked at the MB2 design again and realised that it had a low-back design with a segmented teardrop canopy. Where As OTL the later MB3 had a high-back fuselage with a comformative canopy. At this time my research has found no reason for this. Also OTL by the time the MB3 flew the advantages of the Malcolm hood as used on the Spitfire would to me seem to have been obvious, so why was it not used on the MB.3? I see some interesting PAM reasoning and changes hatching here
Were any of the Bristol radials ever considered?