British "S-Level" Mathematics Books

Question

The British S-level exams (not to be confused with A-levels or O-levels) were said to be challenging exams that were used to select who got a place at the University of Oxford or Cambridge.

Is anyone aware of:

1. The books that were used to supplement this exam
2. Rigorous books generally used in this era in Britain (1960s and before)
3. Books containing exam questions from these papers (or where I can find past papers) or questions at a similar difficulty.

Answer 1

The book that I mainly used (for pure maths) was

Further Mathematics by R. I. Porter (first published 1962 by Bell).

It has plenty of past 'S' level questions at the back.

Answer 2

Definitely "Extending Mathematics" by T.J.Heard. This book is an old A-level maths book and comes in two volumes. It includes many challenging "STEP type" (Sixth Term Examination Paper) problems and in the Preface the author said he wrote it to cover the whole S-level mathematics syllabus. In the second volume, I was also surprised to find a few IMO problems at the end of the last chapter under the heading "miscellaneous problems". They all had a combinatorial flavour. Also, I only found this book because I saw that "Jack Shotton" (~2006 UK IMO team member) recommended it in an old thread in the asknrich forums.

Hope this helps!