I have never seen or heard this plan before. Interesting story behind the P-75. Came close to put into action, but too many problems that push it back. However, I think the Germans 109 and 190s would outmatch it.

Crew: One
Length: 40 ft 5 in (12.32 m)
Wingspan: 49 ft 4 in (15.04 m)
Height: 15 ft 6 in (4.72 m)
Wing area: 347 ft² (32.24 m²)
Empty weight: 11,495 lb (5,214 kg)
Loaded weight: 19,420 lb[7] (8808 kg)
Max takeoff weight: 18,210 lb (8,260 kg)
Powerplant: 1× Allison V-3420-23 liquid-cooled 24-cylinder double-Vee, 2,885 hp (2,150 kW)
Performance
Maximum speed: 433 mph (697 km/h) at 20,000 (6,100 m)
Range: 2,050 mi (3,300 km)
Service ceiling: 36,400 ft (11,100 m)
Rate of climb: 4,200 ft/min (21.3 m/s)
Wing loading: 39.8 lb/ft² (194.3 kg/m²)
Power/mass: 0.21 hp/lb (0.34 kW/kg)
Armament
6x 0.5 in (12.7 mm) wing mounted machine guns
4x 0.5 in (12.7 mm) fuselage mounted machine guns
2x 500 lb (227 kg) bombs