The mechanism has two parts - a hinge section which is fixed to the hollowed out head, and the eyes which are part of a device to move them side to side and up/down. The eyes section connect to the hinge by a clamp, which allows adjustment to the eye sockets. The hinge has a return spring eliminating the need for hard wire controls, in favour of cable/cam.



The eye mechanism front view



Eye mechanism rear and cable connections



The assembly fitted to the head



The face, eyes fitted. I have made a video of the movements, but not able to post here. 



Jim,
Thanks for your comments. I would want to use a speed controller for the motor. Have you used speed control, and if so, is there  power loss ? 

Regards,
Gus

Keep safe