The Secret War 1939-45 by Gerald Pawle (1913-1991) with an introduction by Nevil Shute {Norway}
I found e-book downloads of this while Googling for uses of 'equipment' in the plural for a thread elsewhere.
https://archive.org/details/secretwar193945007234mbp
First published in 1957, it was reprinted by Nabu Press (September 16, 2011)
http://www.amazon.com/Secret-War-193...dp/1245668463/
Which has a hilarious note "This is a reproduction of a book published before 1923. This book may have occasional imperfections ..."
It's about the weird and strange inventions that appeared out of times of hardship during WW2 some of which even worked!
I edit to personally recommend it.
Usual scan/OCR artefacts like 'dock' for 'clock' and footnotes run into the main text but readable.