Okay, here is an idea which has been flown around the park a few times in the past. Why not add the JU-52 to the plane list. Yes it was a cargo, troop transport with guns, but it also was a bomber. Okay, so it is slow and not a great ceiling, but think about it. If you see one, you would not know if it was carrying troops, supplies or bombs. IT would add a lot, IMHO. It also could make it just a bit harder to be shot down with the MG's.
You could have the loadout in the hanger, as with all planes, but with the option of bombs in place of supplies or troops.