The latest Guy Ritchie flick “The Ministry of Ungentlemanly Warfare” has a spine of true story to it, even if it does all it can to amplify a long-declassified World War II tale with enough dead Nazis to make “Inglourious Basterds” blush.

The result is a jauntily entertaining film but also an awkward fusion. Ritchie’s film, which opens in theaters Friday, takes the increasingly prolific director’s fondness for swaggering, exploitation-style ultraviolence and applies it to a real-life stealth mission that would have been thrilling enough if it had been told with a little historical accuracy.

In 2016, documents were declassified that detailed Operation Postmaster, during which a small group of British special operatives sailed to the West African island of Fernando Po, then a Spanish colony, in the Gulf of Guinea. Spain was then neutral in the war, which made the Churchill-approved gambit audacious. In January 1942, they snuck into the port and sailed off with several ships — including the Italian merchant vessel Duchessa d’Aosta — that were potentially being used in Atlantic warfare.