I just finished reading The Archaeologist was a Spy: Sylvanus G. Morley and the Office of Naval Intelligence, which describes the efforts of an American Mayan archaeologist hunting down German submarine bases in Central America during the First World War. It is a quite awful book, filled with hyperbole about Morley's capabilities as a Mayan scholar and a spy. I can say little about the former, but the book itself does a pretty good job destroying the latter assertion. Rather than "the greatest American spy of World War I," Morley comes off as an amateurish bigot who spends more time blacklisting German-born residents into poverty rather than recruiting a few to gain actual intelligence. As the authors are both old-school American Southwest historians, it's understandable to see why they default into hagiography rather critical analysis; but, their lack of expertise in the history of espionage limits them to relying on secondary sources to provide the background for Morley's rather listless "adventures" in Latin America. To top it off, the book ends with a mean-spirited attack on Franz Boas for his calling out Morley and others for "prostituting" their scientific credentials as cover for their intelligence operations. I'm not sure I agree with Boas, but the authors' assertion that the father of modern anthropology was a pro-Kaiser traitor seems pretty far-fetched, and they completely ignore the role of political factions and anti-Semitism in the anti-Boas backlash. The Archaeologist was a Spy does nothing to topple off Jeffrey Dorwart's two-volume history of ONI as the only really solid book to read on the subject.
However, the book does provide a good description of WWI-era intelligence work in Latin America, and gives a number of details on ONI tradecraft. There is a P Division-era scenario pretty much ready-and-waiting here, especially if paired with some of Mayan background details from A Resection of Time. The Deep One handouts serve as a little more than red herrings in that scenario, but could serve as the meat of a WWI-era scenario here.