Thank you CB, I appreciate it.
Agpie, from your pictures, it looks like you may be getting too much bottom heat and not enough top heat. These are possible solutions to remedy your situation. You may try to move the stone a bit closer to the front of the MBE to give you a slightly larger airflow gap in the back. That might help even the heat a bit more. Also, I don't have the inline regulator open full blast. It's about 1/2 open or less maybe, but I'm also using a 180K btu burner. I'll check again next time I bake. But you'll have to play around a bit with how much heat to pump in to get an even bake. I usually load at a floor temp of 650F for a 4min bake. Go higher for shorter bakes and lower for longer bakes.
Also an important thing to note about the airflow director, as Toddster has figured out, is that you have to figure out where on the stone to place the pizza so that the hot air that is directed down is coming down directly onto the rim of the pizza. You have to eyeball it a bit and adjust the placement of the pizza with each turn to get that optimum heat exposure to the rim. This will help you adjust your top heat in the LBE/MBE.
A 2nd adjustment to consider is the actual angle of the air deflector. You may have to play around with increasing or decreasing the angle of the deflector to maximize the airflow onto the rim. Either bend it up or flatten it a bit to control the amount of airflow. Otherwise your crumb looks great.