Sad as it may seem they will have the data plate and that is more or less all that is required for a ground up restoration, even that may be replaced, but that's basically all the CAA req for a "rebuild" that's why when I see Spitfires, Hurricanes etc described at airshows as a genuine WW2 aircraft, I have a little chortle. One I know that was rebuilt off a gate and relatively intact ended up containing a leading edge skin and the plate, the rest was new. There are a few about that are more or less complete, but they are a rarity.