They could have had colored metal for the walls. Like ColorBond.
I want to know what fabric those quilts are made from, they sure lasted.
Rayon, protected from UV by the shields.
A couple of days ago my housemate pulled out a rayon aviator's escape map of Europe his girlfriend found in her grandfather's things. I was immediately in awe. It was in pristine condition, the same as the day it was printed, 70 years later.