OK, my bad.
But then I'd like to know now the following: Why hasn't the 410 been added yet?
My misconception came from the following text, that, now I read it again, doesn't imply that some sort of periscope was used for aiming. I'll add the text because it gives a nice idea about how they functioned and were capable of:
"Two 13mm MG 131 guns in faired blisters, one on each side of the fuselage, remotely sighted and controlled by the rear-gunner. These two blisters are mounted on the ends of a barrel set across the fuselage and carried on annular ball-bearings on inner walls of fuselage. Through a torque multiplier, driven by a small electric motor and trains of gears, this barrel may be revolved to elevate or depress the guns, or further geraring within the barrel may traverse the guns. All movement of the guns is controlled by a pistol grip in gunner's cockpit. The guns may be elevated or depressed through a range og about 70 degrees and traversed independently of each other through about 40 degrees from the sides of the fuselage. The guns may also be fired together towards the rear. A contact-breaker device interupts firing when the guns, which are electrically fired, are pointing at any part of the aeroplane structure."[/b]
