Why make it any harder than it needs to be. Go to Bristol, sign up for the website and go through every question at least 3-4 times until you are getting at least 90 odd percent in their mocks. Then at the brush ups you can actually concentrate on learning a few things as you will more than likely know all the answers anyway from the online database. If you get less than 90% in any of the CAA exams then I would be mightily surprised.