Anyway, a few proposals.
A high performance High Altitude interceptor. Utilizes a supercharged, fuel injected V12 engine, with a AS-AC18 firing through the propshaft, which is kept light due to being reinforced with High quality Steel. (Molebdynum steel?) Enclosed cockpit, retractable landing gear, scope. An additional armament of 4 AS-1924's is present in the wings.
As an added bonus, introduce combat flaps and a War Emergency Power system
This is if we go the quality over quantity route.
A cheap yet capable interceptor. Utilizes a supercharged, fuel injected V6 engine, optimized for fuel efficiency. Enclosed cockpit, retractable landing gear. Armament consists of 2 nose mounted AS-1924's with interrupter gear.
As an added bonus, introduce combat flaps and a War Emergency Power system
Lightly armed, but this should make it cheap and fast.
A triple engine medium bomber (2 in the wings, 1 in the nose). Supercharged, fuel injected engines allow for fuel efficient flight, even at high altitude. Carries 1 ton of bombs in an internal bomb bay and is equipped with a bomb sight.
3 gunners are present. 1 gunner operates a cannon mounted in the tail, another operates a twin machine gun dorsal turret, another operates 2 machine guns on each side of the plane.
For the simple reason that I believe that we can't afford the massive box formations that the B-17 utilized, and that seeing as we have no high altitude escort plane, making a big bomber will only succeed in giving the enemy more scrap material. Hence, optimized for speedy flight at lower altitudes.
Note: I don't see much use in further upgrading our current plane. It's rapidly becoming obsolete, utilizing an open cockpit, no optics, unretractable landing gear, and all that.