The case of It's a Wonderful Life has shown that specific parts of a movie can be in the public domain while other parts aren't, even down to the music within a public domain scene.

For the dreaded special editions of Star Wars, only Jabba's stupid face or the specific shot of the Death Star exploding with that ugly-looking ring would have a copyright of 1997. The original scenes cleaned and restored would still have a copyright of 1977.