Incidentally, the book is also available on Amazon, both on paper or Kindle - it's going to be next on my list. Thanks for posting this, Jolly.
Last time I was at my mum's I found a box of old stuff my dad had hidden away, medals and souvenirs and what-not, which contained quite a few letters from the front from my paternal great uncle from 1917, followed by a telegraph with his death notice and a lock of his hair (taken from before he died, obviously). I didn't have time to go through them, but I need to make sure either my brother or I rescue them.