A break in the summer holidays is NOT allowed, the exams for Bucks are at the very beginning of October, you really must keep up the momentum during the holidays.
AFN are easier than the real tests, as there are many tests which replicate the real thing, I would leave these alone and use them to dip into [ sections at a time as and when ]
I would get onto the Tutors E papers, followed by Susan Daughtrey [Bright Sparks] THey both look like the real tests.
http://www.elevenplusexams.co.uk/epaper ... =f&c=1&p=6
You could also use the Tutors CDs, to prevent boredom of pen and paper tests. Only use The tutors CDs as these are the only ones that are truly Bucks specific.
Ps you say the NFER are 80 questions 50 minutes are you sure, have they published a new set, they are normally 85 questions and minus HIKNOS [ as identified by IPS]