As a relative local, but no child that age, what is the catchment school of house 1 if your son doesn't pass his 11+?
I've been there and if my DD's hadn't got into RHS, it would have been Bilton, which we weren't happy with. Years ago there wasn't much difference between AQS for the grammars and selective at Ashlawn. It's fine if it is Ashlawn and you''d get a space as I've only heard positive things about it.