Chris, I did basically like Matt said but I used lard seasoned w/ my favorite rub,smeared that all over everythiny exept the inside of the fire box, I also took a few pounds of fat and seasoned it and put it on the grill were you would put a brisket (make sure to put a amuminum pan in the bottom of the pit under the fat). My fire box is similar to your inside,I just put 2 red bricks on each side to elevate the fire grate a little. To start mine I use a 5# bag of charcoal and once it ashes over I satrt adding wood and cooking.When I seasoned mine I did like I said above for about 10 hrs w/ mesquite and oak.
Here is mine in its better days...it need work at the firebox now,it is about 18 y/o.
