Pic on Grandpa's post looks like the wing of a bomber or transport aircraft of some type. Early war possible, maybe in the 30s. Short engine cowling would indicate only a single row radial. At or under 1000hp. Two blade props were pretty much done by early war. At least as a design standard for anything other than a trainer.
As there is no location posted on the pic, it could be from the Pacific as much as the Med.