Kind of a recap for those who have considered how to lower chamber temperatures , hold in the smoke, and get a longer wood burn.
I installed a valve using adapter fittings to join a 1/4" NPT valve to a #6 SAE flare fitting. Made a cast iron chunk pan using a chinese cast iron 10" skillet and carriage bolts for legs. And sealed the doors with some nomex 1/8" thick gasketing. This smoker is my main go to for small batches. I use the big PS4400 for large loads.