I’ve decided to adjust my research by taking smaller steps more frequently.
Yesterday I installed the RGA to get a clean baseline for the vacuum system.
It didn’t detect much! Which is good news:
I also spent HOURS organizing the lab. Getting wires off the floor, shelving, etc:
And got a stethoscope for future vacuum diagnostics:
Prometheus Fusion Perfection 
ultrasonic leak detector is way better than a stethoscope.
http://tinyurl.com/42y2thr
Or pressurize with refrigerant to 100 lbs and use a refrigerant leak detector.
http://tinyurl.com/3eehla3