The Autobiographical Tolkien - 'Leaf by Niggle'...

[Guinevere]

Browsing through Tolkien's letters , I recently came upon a sentence which ties in nicely with Niggle's Parish! I thought I'd share it with you!

from letter #45 to his son Michael, written in June 1941:
"There is a place called "heaven" where the good here unfinished is completed; and where the stories unwritten, and the hopes unfulfilled, are continued."

So he had this idea, years before writing "Leaf by Niggle".
(Too bad I didn't discover this before your lecture, Esty!)