Hi Jester,
>D. 520 is in roughly the same class as the Hurri I.
Hm, I'm not sure that's an adequate description.
The D.520 airframe was in the class of the Spitfire and the Me 109, but the engine was not in the class of the Merlin or the DB601.
The Hispano-Suiza gave the D.520 good high-altitude power - I'd say from 5 or 6 km up, the D.520 enjoyed competitive performance.
However, at low altitudes the engine wasn't competitive at all, so even a Hurricane I might have been better there. (I don't have Hurricane performance figures, but the D. 520 topped out at 420 km/h at sea level.)
With regard to manoeuvrability, the French found that the D.520 had a turn rate and radius equivalent to their captured Me 109E, but thanks to its slats, the Messerschmitt could ride the stall safely while the D.520 tended to flick out sooner or later.
>To make it really interesting would be to pit them against early versions of the the 109 like the D & E-1 that were the main LW strenth during the BOF.
Well, the E-1 had almost the same performance as the E-4. Against the baby Messerschmitts, the D.520 would hold the speed advantage, and (except close to sea level) the climb rate advantage too. The light-weight Bf 109B/C/D would outturn the D.520 easily, though.
Regards,
Henning (HoHun)