I think the facecast I have was from the amicus film, The house that dripped Blood - it's the only Cushing film I can think of where his head would have needed to be copied, although in the film the mouth is opened in a scream. Still an easy enough job for the SFX guys to take care of if they used the same lifecast as a base.
I've opened up the eyes today, resculpted the nose, worked on the ears and done a bit of 'de-aging'.
I'll get some more pics up soon!
Al