I'm bulding my 1/72 Revell Gato as the Tambor class USS Tautog as she was at the time of the Pearl Harbor attack. I know early war subs were overall flat black and I have here an image (from Navsource) of the USS Trout, also a Tambor Class boat (from a different yard), as she was in March of 1942.
USS Trout
I want to use this and other images of the Trout as a weathering guide and was wondering what I should use as an undercoat that would be exposed from the pealing black paint. Would the exposed areas be a gray undercoat or exposed steel? I'm leaning towards gray paint. Opinions?