Just for kicks and giggles, take the Tu2's loadout of 88 submachine guns and use that concept in a plane with a larger bomb bay like the lanc.
I also vuagely remember reading in a book about a PT boat crew that took the turret off of a tank and placed it on the bow of thier boat for the extra firepower; they probably had to strip the turret down to the gun and the traversing ring gear to keep the boat from being too top heavy for sea but it still would be fun.