Dear,
According to the book "Gente dell'Aria - Giorgio Evangelisti", the Jona 11 project was a 3-engined fast bomber designed in March 1938.
The aircraft should be engined with 2 radial Fiat A.74 in the wings, and a pushing Isotta Fraschini Asso XI (In line engine).
In October, however, Jona designed the J.11/C, a 3-engine fighter based on the bomber design and motorized with 3 Isotta Fraschini AS.L. 121 RC 50.
The projected armament was of 2 machine gun of 12,7 mm, and 2 machine gun of 20 mm, plus 300 kg of bomb; while the performance was calculated in 600 km/h at 6.000 m altitude.
Here the 3-view of the Jona 11/C.
Regards.