Thanks for that lovely response. Stories from a lifetime are precious. One of my minor hobbies is helping people to collect their stories into a book. There are a few on Amazon that I had a hand in. Right now there's an elderly lady (92!) who is compiling a book about her husband, who died a few years ago from Alzheimer's Disease. We are racing against the clock to get this book out (that is, time is not on our side). But it is so satisfying for her to tell this story and to know others will read it.
If that is something you think your father-in-law might like to do, I'm sure everyone could learn from what he has to tell us.
I wish you well and I wish you many more years to enjoy his company.