Soldato
Subject sort of says it all - my son is applying for uni and I'd love to be able to throw his personal statement past someone for any comments!
Its mixed as you can include that in your personal statement and/or teacher reference. Generally I would prefer it to be in the teacher reference, but if its in the statement then it should only be nothing more than a footnote.
Oxford would be tough to crack with those GCSE's even with special circumstances. Though its important to remember that grades are judged not in isolation but comparative to a students measure of disadvantage which is determined by your postcode data (Polar and Acorn) and GCSE/current school stats.
In terms of MAT score its generally considered that shortlisting starts around 68, but the average of successful applicants is 75. Mock exam papers are readily available on the internet for free, so hopefully he has/will start to go through these?