This sentence from Tolkien's letters ties in nicely with Niggle's Parish:
	Quote:
	
	
		| 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"!