I saw an episode of The Woodwright's Shop a few years ago called The First American Woodworkers and it had a neat little demo of mask carving. The craftsman used a hatchet to shape the face and a metal gouge to make the hollow. If I remember it correctly, the only other tool he used was a pocket or small carving knife for details and the eyes. He used "modern" tools, so I'm not sure if this helps you.
Afraid I can't be of more help than that. I've tried my hand at carving before, but I usually end up just carving my hand. I start at the woodpile, stain some birch, and end up with a blood-sacrifice to Fire (and a sacrifice of profanity to Air).
It looks like PBS is starting to post the videos online; they have the past two seasons up, but they haven't gotten back to that episode yet. If you're interested I can keep you updated on their progress.
Apologies if it's bad form to dredge up old threads.