What a wonderful experience. Like you, I had wondered about how compatible my parents were and what had drawn them together in the first place. They were two very different people. Reading those letters made me see how much in love they were.
Thank you for sharing this. It's a writer's hope that what I say will mean something to someone else. I hope you consider transcribing those letters, or putting them into a photo book, or writing a bit about what you discovered. Stories shouldn't be forgotten.
I can't tell you how much I appreciated you responding to this. My best to you and yours!