This is a little late but I purchased one for a club event and a year or so later I made one myself. I suggest buying one, not because the process was difficult, but because its a whole lot cheaper.
I deboned the chicken and duck completely, but left the wings and legs on the turkey. The chicken was stuffed with rice stuffing, covered in a cajun spice mixture, then went into the duck with wild rice stuffingand more cajun spice mix, the duck/chicken was then placed inside the turkey with more stuffing. Then the turkey was sewn up, along the back bone and more cajun spice mix rubbed on the bird. The finished produce looked a great deal like a regular turkey.
The cooking was the interesting part. Cook at ~190 (I can't remember exactly what the temp. was) for 13 hours. I started it at midnight got up at 3:00, the juices comming out of the bird were amazing. The juice had to be pulled off every few hours and you can not believe how good that juice really was, makes my mouh water thinking about it.
If done well the bird can be sliced like bread (no bones) and the layers of turkey, stuffing, duck, stuffing, chicken, stuffing are a sight to see. Absolutely excellent. I'd be glad to do it again, but my wife says NO. Why I don't know.