Walker said she and her sisters always knew the letters were there, tucked safely away in her mother's top drawer, but they didn't get to read them until after the death of both her parents.
"I'm not sure if it's because we weren't interested or because we knew they answer would be no, but we never asked to look at them [the letters]," Walker said.
"They are very personal, as you'd expect, but Mum's letters to Dad also described a lot about what was happening in Rotorua at the time and also what their friends and family were doing. The written history is very special."
She said it was lucky her mother was a hoarder of "all things important".
"I think it's quite amazing my father returned with letters considering they had to carry their personal belongings with them."
Book co-editor Matthew Martin said the book had been put together by a hard-working team of dedicated volunteers and was an important part of the history of the district and the people living in it.
"Not only does it tell the personal stories of our people, in their own words, but it also marks an important milestone in the history of our nation," Martin said.
"We have been fortunate to gather together these memories, as some of them would have soon been lost forever, and we hope the book is supported by the community.
"Most of the stories are authored by the contributors themselves while some of these have been interviewed and their stories compiled by a small team of volunteer interviewers and writers.
"Many of the stories recall combat experiences while others are of civilian – even childhood – memories impacted by war.
"The book is filled with excellent photographs and illustrations, from wartime and today, and adds to the colourful and diverse history of the region.
"We encourage people to attend the launch to help make it an even more memorable occasion and thank everyone who has been involved with the project over the past few years."
Touched by War - Wartime Memories will be launched in the Discovery Space at the Rotorua Library on November 10 from 11am.
All proceeds from the book will go the Rotorua RSA Poppy Fund which is for the welfare of veterans and their families.
Following the launch, the book will be sold exclusively at McLeod's Booksellers for $29.99.