Corsi has the written documentation. It was an evening class. It was not a correspondence class. I, and many others have registered for school on Saturdays and gone to Saturday classes.
Why do you have the huge need to try to debunk that which you admit you have no knowledge of?
At the University of Washington in August of 1961? Really? Which ones?
During a regular term, you might have a Saturday class. But in August, 1961, the school was pretty much shut down as soon as summer quarter finals were over which by my recollection was August 10.
The issue is August. Corsi says she was there August 19. Starting class on Saturday? When the school is shut down? The August 19 date doesn't demonstrate she was there. Among other things, the real date is probably September 19 and the August 19 simply represents a misreading of the note on the transcript. And that doesn't demonstrate she was there then either.
The "C" is a problem for my analysis--I have just looked at a fall quarter 1964 transcript for someone else for a class that was done out of state--by mail; no C; only an X. So I wonder about their classification system.
But the real issue is the timeline for her movements. There is floating around a letter from the University which sort of supports Corsi's original story but the August 19 presence date is wrong.