You could look at Greyguy's mechanical head construction - there was a long thread on the old message board, not available for now, and a few photos here on this board somewhere. It's not exactly the same of course - he wasn't trying to replicate McKinnon & Saunders designs, just achieve the same sort of results. So it's another puppetmaker's approach to putting mechanical movements in a puppet head.
If what you want is to duplicate Victoria's mechanisms so your replica is as near the same as possible, both inside and out, that's not going to be easy. The Corpse Bride, Invitation to the Wedding book didn't give anything away, it was more an "art of" than a "making of" approach. It had one photo of several duplicate head armatures, with all the gears hidden inside the fibreglass underskulls. A few glimpses have surfaced on the internet, but the ones I've seen never quite show enough.
It does require some very small scale, precision engineering work. I wouldn't even attempt it in that scale, I'd probably make a much larger close-up head if I needed to get shots of the subtle movements the CB heads were capable of, and use a simpler head on the main puppet. Ron Cole, who has done facial movement as good or better than that seen in Corpse Bride, used big puppets in order to fit the mechanisms in, and went for a cable control system with external controls something like an animatronic puppet, only operated a frame at a time. He has a tutorial that shows some of how he did it, but not quite all - considering the years of work he put in to develop it, I don't see why he should give it all away for nothing. But hats off to you if you want to have a go at it!
They used gears to scale down the movement - I would probably opt for screw mechanisms to get the fine control, because screws and threaded rods in different sizes are far easier for me to source, and I can tap holes in metal parts to give them something to pull against. But it depends on whether you want a way to achieve a moving face, or whether you want to be able to say you did it the same way so it's a true replica.
Found a thread on head mechs in the Armatures section, which led me to a link to a photo at Lio's Stopmotionworks site -
Hi I have seen the Victor puppet up close and its real cool!
You soom real skill to do !
Even M&S sorce out the fine mechanisms as they do the design and prototype but leave the precision work to a machine shop.
There is a soarce in NY that can make the worm drive for you.
My heads that I made are my own little variation of the mechanical heads made with screws and nuts like a breathing mechanism
The CB heads still use a cable mechanism for the actual pulling on the face so Ron Cole's tutorial on making the face layer and skull core is still valid regardless of scale. The largest of the gearing mechanisms was just for the swing arm to open and close the mouth. This was important so the mouth would not open or close regardless of the tension put on different parts of the face with the other mechanisms. The remaining mechanisms were for the facial smile and frown can be though of like guitar tuning pegs (worm screw/gear drive set) being able to keep tension where they are set to pull on these cables. The only difference being that they are dual counter ran so turning one direction you will get a loosening of one cable and tightening of the other. The eyebrows were ball and socket as well as parts of the lips.
So depending on scale you might try looking at using guitar tuning pegs for an easy start.