Hey Cap'n,
That's pretty funny actually. I inherited a cookie sheet that my wife had worn out. It had a non stick finish on it. I removed the finish with a wire wheel flattened it out and cut it to fit the cooking side on an angle. It goes from just above the opening from the fire box out about a foot or so into the cooking chamber. It doesn't but right up against the fire box though. I leave a gap for some heat to enter right at the fire box. I got the idea here:
http://www.amazingribs.com/tips_and_...t_smokers.html there are a lot of good ideas on that site. I like the tuning plates idea. They are steel plates that sit in the cooking chamber even with the bottom of the baffel. You can use different sized plates and adjust the gaps between them to adjust how much heat comes up where. I was thinking about making some out of spare floor tiles. My thinking being that the ceramic would help regulate the heat better.
I also made a basket out of expanded metal for the fire box to hold more coal. I had to make it 12 inches square and 3 inches deep so it would still fit through the opening in the fire box. The problem was this allowed too much air to enter the fire box and go around the coal box rather than feed the coal from the bottom. I added a baffle from the top of the vent side of the fire box to the bottom of the coal basket. I also extended the flue down to the level of the grates to trap heat in the lid. This was a great help. I found an aerosol can that was just the right size to fit in the flue and cut the ends off it.
I'll take some pics tomorrow. I just cleaned the grill so this is a good time for pics.