There's a new anthology of Belloc writings: The Eyewitness: an Anthology of Short Stories. You can find more information here. From the site: "Written with an eyewitness quality, these previously uncollected short stories of Hilaire Belloc transport us to realms of the past and realms of fantasy. This unique volume contains 25 short stories and fables -- many appearing in print for the first time since Belloc’s death over fifty years ago."
The book doesn't appear to be available at Amazon yet.