I did these tests myself and all the Brewster was said to be able to do turned out negative. It did go to about 580 mph from a dive of 25,000 feet for about 10 seconds starting from 150mph.
I decided to begin pulling out about 3 seconds after hearing airframe stress and decided to do the E retainment test. Starting from 400mph I did a 180 degree turn (not sure how many G's, but there was plenty loss of peripheral vision) and ended up losing 50mph.
I do not have a film ATM, but I could easily do another test and post it later with details of how I carried it out, if you all want.