Hello!
I know that someone has already mentioned Ambrosini SS.4 on our forum, .
This is one of the more interesting aircraft I've ever seen (a truly Italian elegance).
It was created in 1939. Unfortunately, he was too innovative (but not nuanced) and not entered into production.
General characteristics
Crew: 1
Length: 6.74 m (22 ft 1 in) [2]
Wingspan: 12.32 m (40 ft 5 in)
Height: 2.49 m (8 ft 2 in)
Wing area: 17.5 m2 (188 sq ft) [2]
Gross weight: 2,449 kg (5,400 lb)
Empty weight: 1,800 kg (3,968 lb)
Powerplant: 1 × Isotta-Fraschini Asso XI R.C.40 V-12 liquid-cooled piston engine, 720 kW (960 hp)
Propellers: 3-bladed metal pusher propeller
Performance
Maximum speed: 571 km/h; 308 kn (355 mph)
Stall speed: 110 km/h (68 mph; 59 kn) [2]
Armament (conflicting information) : 1x20 mm + 2x12,7 (best hypothesis).
Other sources give information about three machine guns or three cannons.
Cheers.