You might want to try contacting Lynnwood (Lynn) Dunn, ASC. President,
FilmEffects of Hollywood for info. Years ago I worked for Lynn and while
doing a holdout matte for West Side Story I came upon some books of 4x5
prints. They were the details of the matte scenes for both King Kong and
The Hunchback. At that time Lynn was saving them for the "Hollywood
Museum." Lynn had kept all sorts of mechanical bits and pieces, who
knows what else is up in his attic.