Parabat, Lansen73 and KLP,
Thank you all for your kind words.
Jack,
I don't know how often the stressed metal phenomenon happens. I guess it's an equation of how long the airplane is in the air and how stressful are the maneuvers.
Maybe even how the airplane is maintained... I know that you can find it even in modern aircraft, today.
Any way,
The stressed metal effect is more obvious from a certain point of view, and that is the rear of the plane and with certain angle of light falling onto it.
check this picture here and look at the plane in front, especially it's left wing, you can almost see every panel.
In Courtesy of www.luftwaffephotos.com
Just like forced perspective dioramas, this is sort of like "forced perspective stressed metal" concept.
This is something I was seeking and trying to achieve for a while.
I myself has some thoughts about how it is emphasized, and perhaps I will tone it down a bit in the future. However, just like you said it, it is more visible from the back of the plane.
From other angles it is less visible, again, a concept to fool the eye.