American Museum of THE Moving Image

2001 A Space Odyssey monkey Marlon Brando-The Godfather lifemask Brando Godfather plumpers
Freddy glove, chest appliance and sweater Close-up of chest appliance Freddy oversized sweater
Dustin Hoffman lifemask for Little Big Man Dustin Hoffman handcast Little Big Man Display
Old man hand mold Old man prosthetic Little Big Man head mold.
Appliance molds Little Big Man display piece
John Hurt Elephant Man lifecast Elephant Man appliance display #1 Elephant Man display#2
Exorcist full body with turning head Exorcist front shot Close-up
Starman transformation scene

I believe over one hundred different heads were used for the transformation scene at the beginning of the film.

Yoda from The Empire Strikes Back Yoda close-up
Enemy Mine head piece, arm and hand Wolf from Wolfen
 
Chewbacca 2001-1
   
2001-2 2001-3