I got it all back together yesterday, and while I had it apart and the tank
at one atmosphere I added a single quick coupler in front of the shut off
valve to the rest of the shop. Now I don't have to go through a full start
up and shut down to air up a tire, and if I need to blow out the filter
screen in one of the separators or the air dryer I can without getting the
roll around out of the garage.

Seemed to take forever to come up to pressure, but I stood there patiently
and slowly adjusted down the pressure shut off screw as it approached my
desired shutoff pressure. Nailed it about perfectly first try. Then I
popped the safety valve and it kicked back on about 10PSI above the highest
minimum pressure I need for any automated or semi automated equipment.