Hi Wine and Cheese,
Do let us know if we can help. We are a local agency based in Balham and we specialise in highly qualified teachers and tutors. Here is a bio of one of our tutors who may be able to help your boy should you still be looking.
C is a fully qualified teacher with a PGCE in Secondary Mathematics from the University of Oxford, an MSc in Physics and a PhD in Economics. She is an experienced Mathematics tutor who has a great deal of experience teaching in schools, as well as tutoring 1:1 and in small groups. C has taught GCSE and A-Level Maths and Further Maths for many years in secondary schools and is familiar with all major examination boards (Edexcel, AQA& OCR). C is tutoring online at the moment due to COVID19.
Jess at Mentor Education