Here is a reply I have received from John Mason, who had wanted to send this message to the mathedu list but could not since he was not on his regular e-mail connection, so he recommended that I sent it.
Message from John Mason follows:
In case it is of interest, the book Thinking Mathematically (1982) which was inspired by Pólya has been revised in a second edition Thinking Mathematically (2010) with a new preface, 77 new problems and all problems linked to curriculum topics, and a new chapter relating the 'processes' to the language of 'people's natural powers'.
The audience is bright school children, pre-service teachers, students moving to university, and undergraduates. The original has been used for 28 years for all those audiences.
JohnM I can't send this to the list because I am not on my usual email connection: perhaps forward for me?