So, essentially, it's a B24 with a 12 hour (in our MA) flight duration, but weaker armament?
Just fly the B24. As-is I am adamant that there is no reason for any flying boat, from any period of the war. Most performed duties that AH completely ignores, and as such without the duties being important, without a reason to do them (some sort of strat?), without a reason to stop them, without some motivating factor to make people use flying boats, and without some impetus to shoot them down in their flying boats, they serve no role in AH.
That's in no way a slight on your desire to have one, Karnak. I merely wish to explain why I feel AH will never see them.