World War II Portrait: The Handmade Booklet

The details of this painting are so interesting to me. The handmade booklet that he is holding in his lap is still a mystery and I plan on researching it more as time allows. My first thought was that it had a leather cover but when I examined the photo even closer I could see that there was a slight indication of a wood grain running through it.( I still need to play around with the color.) The metal brads do appear to be attached to leather straps and then the entire book is looped together with a leather string. The word "Army" is three dimensional and perhaps glued to the wooden cover. I wonder if Pete ever imagined that this booklet would someday be considered rare and unusual and included in an oil portrait of himself.