A partial survey of titles Fr. Ong published from 1941-1947:

"Twenty-two Titles Tell a Tale" (1941)
"Mickey Mouse and Americanism" (1941)
"Spenser's View and the Tradition of the 'Wild Irish'" (1942)
"The Meaning of New Criticism" (1943)
"Historical Backgrounds of Elizabethan and Jacobean Punctuation Theory" (1944)
"A Liturgical Movement in the Middle Ages" (1946)
"Mr. Barnum and the Reader's Digest" (1946)
"Hollywood and Ourselves" (1947)
"Wit and Mystery: A Revelation in Mediaeval Latin Hymnody" (1947)
"Kafka's Castle in the West" (1947)

The medievalist in me is just in awe at a series of letters dating from 1951 which I found in Ong's "The Green Knight's Heart and Bucks" publication file. They are letters to and from Francis Magoun, with whom Ong studied Old and Middle English literature at Harvard and is, or so medievalist lore has it, the model for the cartoon character Mr. Magoo. Magoun suggests that Fr. Ong look up Jess Bessinger, who was in London on a Fulbright. Ong responds that he'd run into Bessinger by accident while visiting the University of London library and that Ong wants to introduce Bessinger to J.R.R. Tolkien. Ong also notes that he didn't know Tolkien directly or met him "facie ad faciem" but that Tolkien was a regular visitor to Chapion Hall at Oxford, which is the Jesuit residence in which Ong lived while staying in Cambridge.

With the correspondence in the 1954 publication "St. Ignatius' Prison-Cage and the Existentialist Situation" is a business card of Prof. Dr. C.G. Jung. There's no indication of why Jung's business card is in the file. I've asked a family friend who has a degree in psychiatry from SLU (and knew Ong) and then went to Europe to study under Jung if he knew whether or not Jung and Ong had met and he didn't. I need to ask around some more.