here is a picture of the last Pit I built. I have been using this for 2 years now.
This took me 4 months to build. It was built all out of new steel. I had the metal shop actually roll the 1/4 inch plate to make my cooking chamber. The chamber has 2 compartments and with the one firebox I can have 2 different temps as I have butterfly valves to help control the heat.