As a professional writer and communicator, I have used this invaluable little book regularly since I inherited a copy from my (late) former boss in 1974. He had dated it 1961, when he started a job editing a shortlived national news magazine called "Topic".
I have been writing for publication ever since, and use this book several times a week. Of course, over the years I've bought updated editions for use at home and at work. I still find it an invaluable guide for quick reference on subjects as diverse as names, spellings of common foreign words, abbreviations, technical terms, dates and many other matters.
Perhaps its greatest value, however, especially in a corporate environment, is as a standard and a reference guide.
If they don't reprint it, and you've any aspirations as a professional writer, get yourself a second-hand copy. You won't regret it!