Thanks guys.
But, the plot thickens....... kinda long, I did a lot of stuff today.

Today I kicked it on and it cooled great. All seemed normal!!!!
(Yes, Old Pearl has healed herself before).
Below are the test conditions and results I saw.

Conditions:
- Engine speed 1400, AC system on full cold, fan Hi, doors open.
- Outside air temp 85. Just the belt-driven fan pulling air across the
condenser (electric fans did not come on, but they do work when needed).
- Allowed it to stabilize for about 5 minutes.

Observed:
- sight glass bubbling away as it's always done since new.
- vent temp 55 degrees.
- hi side pressure 220-230 (maybe a bit high?)
low side pressure 22-25
- low side return line nice and cool
- when I turned it off and left the gauges connected, the low side pressure moved back up VERY slowly. After 30 minutes the high side was back to a normal 100psi, but the low side was up to only 65 psi.

The operating parameters seem pretty close for a normal system. The high side might be a bit high for 85 ambient, but probably due to the less-than-stellar air movement of just the belt-driven fan (see below for more theory).


Possible conclusions:
- Freon level is okay. Cools fine now.
- elevated hi side might indicate a partial (sometimes total) hi-side
restriction, such as in the expansion valve.
- Slow hi-low side pressure equalization after turn-off might indicate
restriction in expansion valve.

ANY THOUGHTS??????

Other trivia:
- late last summer, and earlier this spring, the compressor would randomly
just stop running for several minutes, then kick back in and cycle just
fine. I never got to actually troubleshoot it, cause it would heal just about
the time I got started looking. I assumed a pressure switch or a bad conection (please not the MAS). I cleaned all the connections and unplugged/plugged the MAS, and it had not misbehaved lately. When the "restriction" problem happened to the wife, I thought it was just the compressor off again, but it was running (but not cooling) this time.
COULD THIS BE INTER-RELATED to the current "restriction" issue?
I don't see how, unless the hi pressure was going waaay up, enough to trip the hi pressure switch (450 psi?).

What I'll do:
- Right now I'm leaning to the restricted expansion valve theory.
I think I'll drive it and see if it fails again. Then run the tests again.
If it does act up, barring new evidence;
-I'll get the freon recovered, see how much it had in the system, and conclude if I did have a leak.
- Replace the valve and drier, and maybe a flush-out, depending on what I find in the valve. Replace accessible o-rings.
- Vacuum test for leaks, pump her down for a couple hours, and shoot in my last R12 cache, along with the proper qty of the correct oil.

Cheers,
DG