I'm no good at titles, but here's a bump!
About the title, I suggest that you work WW II and religion in the title, maybe WW II chaplain to vets. Which is kind of what your great grandfather was, even though he wasn't a chaplain in the military, but he did preach his message to the troops, and his sermons often dealt with themes facing military families.
hmm...
Voice from the Past?
Family Folklore, Heard Again?
dunno.
This may help you come up with a title:
What are the stories about? What is the underlying message? What's important about what he is saying?
Note: I don't mean these questions in a critical way (sometimes when you type things they come across the wrong way). What I mean by them is to ask yourself these questions as you go, and they might help you find the "hook", so to speak, that will guide not only your title, but your overall thesis.