Fella, having worked in an ACIO, you need to go down there and speak to them for numerous reasons. They'll be able to tell you the likelihood of getting in there, with your age (which you don't mention). All too often the RAC are generally booked up in the intake aspect, even young guys looking at joining straight from school aren't getting in. I appreciate you want the advice from us crusty old farts, but, the only people that can really tell you the score are those that work in recruiting. Have a look at the threads re joining etc on here by all means, there's lots of guys gone before you asking the same stuff. You enquiring through a careers office and laying your cards on the table isn't a bad thing, get on their books, get all the pre-requisite nonsense sorted first then you are over 75% of the way towards getting a place. Good luck
PS - it's not called an old recruitment centre, even if some of the guys in there are!
i think it should be a little later as all the old crusties who are there because they are to old for the real job are still on there afternoon nap so if you get there by 15.10 you should be ok as naafi break is in the equation also but good luck anyway you could pay a kid to stand outside with a cell phone and he could call you if he sees movement inside