We added a vent to the fire box door.
We added a thermometer to the smoker door. It is sitting around cooking level. We also use probe thermometers in the meat while they cook.
We have now added the wood box. The dimensions are around 26 inches wide, 6 foot long, and 2 foot high. This should really put some more weight on the front of the trailer and help to distribute the weight more evenly. The frame is made out of square tubing metal and the sides are made out of a fiberglass composite panel called Ridgidex. The panels were a freebie and the metal was around $3.00 total. Our only real cost was a few bolts, washers, and nuts, and some screws.
Here is one of the side panels.
Here is the wood box. (We will add a top later on once we decide what we are going to make it out of.
More pictures are on my webshots page - see my signature.