Thought I better update this thread.
I ripped the dash out and installed a new evaporator and valve, a new heater core, a new drying container, and every single seal and oring in the whole system.
While I was in there I even removed the front carpet and cleaned that.
It was scary having the whole dash out but I took my time and everything went back together fine.
On Friday I go back to coolcar to have the system refilled, so fingers crossed.