The funny part about aircraft is that some with horrible-looking wounds make it back and some with very light apparent damage go down. Of course, it could be because their skins are so light you can push a screwdriver through and whose skins form a structural stiffener for the whole assembly and the force of a contact can easily be transmitted to beneath-the-skin components, as you pointed out with the P-51's control cables. Have you seen THIS site, Harlan?
On a related subject, now that B-17 Chuckie has been purchased by a local museum and restoration depot, how hard do you suppose it is going to be for them to get their hands on a Sperry ball turret and nose turret? I think Chuckie is a G model that has had these two turrets removed. I wonder if they are just going to have to fabricate the turrets for themselves? They are certainly capable of it.
Bob