Air Law is not an easy exam to pass first time.
I've now passed 4 exams in the last 7 weeks, 3 of them with marks in the 90's and for all of them except Air Law I only needed 25 - 30% of the allotted time.
I only just scraped through in Air Law - that was a bit too close.
I did use the PPL confuser and could get 90ish in mock exams off it but you can see where I ended up.
I used the Thom books and a study CD and also was in and out of the airpilot, downloaded the ANO, read Lasors - what a sad muppet I was!!!
We have a lot of examiners at my flying club and their advice to me was to cover up the answers and read the question at LEAST 3 times before looking at the answers. There are usually 2 obvious wrong answers but there are 2 where either could be right but 1 is MORE right than the other.
This is where a lot of people get caught out.
If you want to do some background reading - PM me and I'll send you the links to the 3 sources mentioned above which were provided to me by my instructor when I was panicking.
PS A friend at the club told me that Met was another "dodgy" paper as he swotted like mad and only just got through on 75%.