Re: prosthetics...there are two parts, the inner area, which is taken
from a mold of the actor's face, and the outer part, which is sculpted. If
you change actors, you do a different mold from the face of the actor to
create the inner half, but you can keep the outer part the same (based on the
sculpture). Usually you sculpt it to stay close to and accent the actor's
features.

jms