Open the Fowls all down the Back, and bone them, first the Pigeon, then the Partridge, cover them; then the Fowl, then the Goose, and then the Turkey, which must be large: season them all well first, and lay them in the Crust so as it will look only like a whole Turkey
Quoted p 76-7 in Clarkson; I haven't checked it yet in the original. A hare, a woodcock and "more Game, what Sort of wild Fowl you can get" went in surrounding the turkey.
Wacky. I know it isn't really turducken for a host of reasons.
ETA: Oh, I'm a little late to be making this observation:
ETAYA: Any stunt cooking I've ever done pales in comparison to what these folks accomplish: