RE: Junkers JU-52 How to corrigated metal
I saw a Ju 52 a few years ago where the builder had used ordinary cardboard. It was the kind of cardboard used for boxes etc, I.E a layer of corrugated cardboard sandwiched between two layers of flat cardboard. He sprayed water on one side and let it soak for a while. Then he carefully peeled away the soaked flat layer. The remainder was then contact-glued to the plane and when painted it looked absolutely stunning. If I understood things right he had done a lot of experimenting before he found the correct type of cardboard...
Jens