Moose - on the academies, this was a slight concern, which is why I asked. The academies act was amended from the original bill and academies are required to behave in the same manner as maintained schools in respect to SEN on admissions/funding/provision. How it plays out in practice won't be known until spring when places are offered for the first time. They are entitled to be academically selective, but they can't then reject academically able students on basis of SEN status iyswim. For parents of children with any SN this is a concern, for you it is not so much of an issue.
In my limited experience of statementing (being secondary most children arrive with statements, I generally only dealt with BESD cases) childen with ASD did usually obtain statements, simply because their needs were not curriculum access related and were difficult to meet within the normal operation of the school. However, whether you would get a statement now would be dependent on how your LA is operating at present - any SENCO in any local school should be able to give you an idea on this.
Being realistic, and I'm sorry if this isn't what you want to hear, the 'sweeping under the carpet' approach (sorry for generalistic term, couldn't think of a better one) to transition isn't going to be effective, and most likely could be counter-productive. Transfer documents would also have to highlight existing SEN status to the high school so they will be aware of his tentative AS diagnosis, although the detail depends to a certain extent on the efficiency of the primary school in providing information. However, it wasn't uncommon for me to get transfer documents detailing food preferences, incidence of family term-time holidays and various other bits of information so do expect there to be some detail passed on. It is pretty important for the high school, they need to be prepared to meet a child's needs. And if they don't have the relevant information it is the child who suffers. The reason I would aim to get a statement in place before transition is that children with ASD usually present in Year 7 as high functioning but slightly distant socially, however by Year 9 the difference in development can be quite marked however. Puberty is a complex time for any child as we all know, having been there ourselves, but the social side of things tends to take children with ASD a LOT longer to grasp and it can make those last 2-3 years at high school quite difficult to negotiate.
TBH, I think I would apply for the statement if your LA situation is favourable. If not, the decision is more difficult as there would probably be more fight involved and I can understand you not being willing to go through that process. I never mind giving you my opinion on your DS1, but it's hard to know where to draw the line since I've never met him and don't as result have an accurate picture of where he is on the spectrum. It's also hard to balance being supportive - which is the purpose of this thread - with the more straightforward approach I tend to have with parents/colleagues. I'm always slightly concious that I might just offend you, which isn't the intention!
Dog - Good to hear from you. Swimming at 40 weeks, you are fab.
MissJ - Thank you for your rice post, will be using that tomorrow. You are obviously a pro cook, sure you don't want that catering job when your ILs retire? 
