Ah Jeeves, just the man! No paint at all. It was lying in the open ‘on site’ for 35 years then in storage unattended to for the following 35 years. It is now to see the light of day again.
I assume frame 10 is where the flight engineer’s instrument board is mounted. Can’t quite work-out the need for the cut-outs though, and why the bottom edge of the plating is at an angle to what I assume to be the the vertical in-board edge (right hand side of the photo).
Geoff