So this didn't paste into the nice grid I had hoped for. However, it's listed in the following order for the raw score ranges: Physical sciences, verbal reasoning, and biological sciences. So, with a 53 on the physical sciences section, it looks like you got an 8. You can find the scales for all of the AAMC practice exams (except I guess the new 9) at www.emcat.com.
just a forewarning, test 3R is not a very good predictor of the real mcat...the questions were too easy. but of course, it is still good to get any practice in.