Bogdanovich wound up volunteering to play his own part after Welles’s unlikely original choice—the impressionist Rich Little—had to leave the production to keep other commitments. The ensemble is rounded out with longtime Welles colleagues and cronies, including Paul Stewart, who played the malevolent butler Raymond in Citizen Kane. Susan Strasberg makes a lacerating appearance as a film critic—she’s a stand-in for The New Yorker’s Pauline Kael, a famous Welles antagonist—who has come to interview (and taunt) Hannaford at his party. (Other guests include a then-unknown young actor, Leslie Moonves.)

But the cynosure of Hannaford’s film-within-the-film is Oja Kodar, the Croatian-born actress and screenwriter who was Welles’s last muse and lover. She wanders sometimes naked in redface through the action, either pursuing or being pursued by a sensual young man, Hannaford’s star discovery, John Dale (played by a Jim Morrison look-alike named Robert Random), on whom, it is not so subtly suggested, the director has a latent homosexual fixation. These parts of the film—at one point, the interior movie runs for more than 10 minutes straight—play out as lurid, male-gazey fantasy, with psychedelic colors and a graphic sex scene in a rain-spattered moving car.

Kodar, who shares the screenplay credit with Welles, heavily influenced these scenes, and Welles once told a French interviewer that part of the pleasure of making the send-up was that it was precisely the sort of film he himself would never have made. Still, it’s as dead-eyed a parody of its genre—which exploded traditional methods of realistic narrative storytelling in favor of an impressionistic mélange of mood, image, and concept—as the faux “March of Time” newsreel is in Citizen Kane.

Welles shot the party scenes—as if filmed by the guests themselves—in a dizzying mix of formats: Super 8-millimeter, 16-millimeter, 35-millimeter, and in both black-and-white and color. That is part of what made piecing together the finished film—from more than 1,000 reels and 100 hours of surviving footage stored in Paris—such a challenge. Before his death, Welles, who had planned to edit the film himself, had put together a partial 40-minute work print, but he left no detailed notes and his ultimate intentions were not always clear. In the end, much of the quarter-inch tape of soundtrack turned out to be missing altogether.

When the American Film Institute gave Welles its lifetime-achievement award in 1975, he had hoped to use the occasion to help secure financing to finish The Other Side of the Wind. “There was all sorts of manipulation from Orson in Paris through Bogdanovich to include long scenes from the rushes into the tribute on CBS,” George Stevens Jr., who produced the ceremony, told me. “We eventually included some. Orson thought this might be the avenue to completion funding.” Stevens says Welles was “magnificent, cajoling, outrageous, and charming,” and he made a moving acceptance speech that ended with a toast “to the movies, to good movies, to every possible kind.” At least one financing offer was forthcoming, but the Iranians rejected it in hopes that a better one might materialize. None ever did. Welles ended photography on the film in 1976, having captured the whole story, as it turned out.

Completing Wind had long been a goal for Bogdanovich and Marshall, who got his start in Hollywood as an assistant on Bogdanovich’s first feature, Targets, in 1968, and over the years, Marshall had managed to acquire some of the rights. At various times, investors seemed ready to bite. But the project only finally gathered steam in 2011, when Filip Jan Rymsza, a Polish-born producer and filmmaker who had become fascinated with the film and gotten to know Kodar, approached Marshall at a party at the Telluride Film Festival. “I kind of surprised him at his house,” Rymsza recalls. “It was an ambush.” Marshall was skeptical, but quickly realized that Rymsza “knew what he was talking about,” and the two joined forces.