Very cool video! I have a small Earth Oven and while it still needs that outer insulating layer it does make the best pizza! All the family comes running when they hear that I am gonna fire that puppy up!
After watching your video I may try to figure out how to put that other chamber in and a chimney to make it not smoke as much as it does now--it shouldn't be too hard.
I'll just figure out how to put a form in there to hold the chimney and clay/cob mix--probably some heavy paper mache to give it that nice rounded shape.