Secondly, does anyone know anyone who knows anyone whose children have got a place at WGSB or WGSG without being tutored? My son is not seeing a tutor, although I will be helping him myself to prepare.
Yes, my dd did - if by 'being tutored' you mean paid for. I did tutor my dd myself, ie basically covering the Year 6 maths curriculum and doing some practice VR/Maths papers, over the 6 months prior to the exam, and there is excellent support on the forum from old hands like Daogroupie (who despite her name, knows everything there is to know about all the local 11+ exams, not just DAO) to help if you want to help your dc yourself.
For what it's worth, all those of my dd's friends who used paid tutors to help them in the Consortium exams failed - the only ones I know personally who passed had helpful parents instead. I do strongly believe that no tutors care as much as a parent nor know their child as well, so doing it yourself is far more effiient use of limited time (and money!).
Feel free to ask for tips!