Paul,
from your description of running when starter fluid is introduced, it has to be a fuel delivery issue. all other tests and stats would appear to be too deep of an analysis for this problem.
Suggest- feeding some new gas into the carb (from glass jar, not gallon can etc due to potential of fire). Just feed it in slowly while someone starts the car – see if you can keep it running. If it does keep running switch off and repeat the process but using gas taken from the tank. It may be contaminated (water etc) and only picked it up following your 30 miles.
Hope it works out for you- I have picked up a lot from your replied to others questions.
Mike P