The refrigerant was removed from the system by the indp. shop when they diagnosed the problem. This was how they "locked out" the compressor so I could drive it without worrying about the issue recurring.
My "plan" is to have the same indp. shop fill the system once I changed the compressor and drier. Is this unreasonable given the circumstances?
I definitely qualify as a part swapper, including the coolant tank and AOS as well as many other jobs on other vehicles...though I am also familiar with a saying regarding mice, men and plans...
As best I can remember, the AC worked great before the issue started. It was January, though I do not recall any noticable noises or symptoms of problems with the AC. The shop said they pressure tested the system and found no leaks.