Have a look at this page from the School Websitehttp://www.saintolaves.net/?p=admission ... /key_dates
As I understand it the application form does not have to be in until after the Open Day on 1st October ( in fact the application form is not available until the Open Day). Once you have applied to the school to do the exam (which is not until Nov) you then put the school on your Home Authority Scaf. This is certainly how it worked two years ago and as I understand it, the same applies this year.
I hope this helps.
Btw: I'm pretty sure that St Olave's is in Bromley and not Bexley. The St Olave's exam is neither the Kent Test nor the Bexley test , it is specific to the school