Check out Foxfire #3, article begins on page 354. You could modify the framework to suit your needs.
The one my family used is still standing. I guess all the smoke, salt residue, and the other chemicals may have termite-proofed it. It was tin roofed, made of peeled pine logs chinked with clay. Firepit was a hole in the dirt floor. It was about 10-12' by 20' or so. The meat was hung from the rafters for smoking, and then stored on plank platforms on top of the rafters after it was finished.
This is folklore for me, we got electricity about the time I came along.