My wife made the mistake of taking me to another Kitchener thrift store. Sure enough, I found 2 more books with WW1 content. One of the letters sent home between 1917 to 1919 from an American soldier who volunteered early after the entrance of the USA into the war and was sent to the Western Front. The other book is about failed military equipment with a few examples from WW1. I will send you the pictures for the Saturday livestream.
All the songs in the book are on RU-vid if you want musical context for the words. Excellent haul I must say. I've made notes to add them to my own collection.