I have (fingers crossed) got the baking stepping up nicely now. I have used some of the outer shell to act as a shield and to direct airflow towards the front and back of the baking volume. I also moved the RE-72 thermocouples to a higher temperature region and replaced the broken thermocouples. The program is on automatic mode and has currently stepped up to 40C with the max diff reduced to ~4C.

I will continue monitoring for a bit but all looks good at the moment. 

Additionally, our baking exploits over the weekend got us down to 9e-9 mbar when I came in this morning.