On Friday, the freshly restored and reconstructed print of Sergio Leone’s “Once Upon a Time in America” will play as part of the Cannes Classics program at a gala screening to be attended by cast members Robert De Niro, Elizabeth McGovern and Jennifer Connelly, and members of the Leone family.

It will be an emotional occasion, recalling memories of the bitter battle the director fought with the film’s U.S. distributor. Leone’s cut of the film that premiered in Cannes in 1984 was 229 minutes long, but the print that was released in the U.S. was edited down to 139 minutes, with many scenes reordered. The 4K print to be shown on Friday is based on Leone’s original cut, with 25 minutes of additional footage.

The restoration, which was carried out by Italy’s Cinematheque of Bologna at the Immagine Ritrovata Laboratory, with the assistance of Andrea Leone Films and Regency Enterprises, was funded by Martin Scorsese’s the Film Foundation and Gucci.

Scorsese tells Variety that the screening provides an opportunity to remind the biz of the need to protect the rights of artists, another area in which the Film Foundation is active.

“It is always a challenge, whether you’re making your first film or your 21st. There’s often a conflict between the need to make a commercially viable film and the artistic intent of the filmmaker, and it can become more pronounced the more expensive and complex the project,” he said.

“Unfortunately, Leone was never able to present this film as he originally envisioned and spent his remaining years trying to put it back together. This restoration gets us as close as possible and is a tribute to Leone and a gift to audiences, who can now glimpse the epic he wanted them to see originally.”

Leone’s daughter Raffaella Leone says that the partners in the restoration project faced a number of challenges. “The hard part was to find, re-assemble and restore the cut scenes because they were in very bad condition. What will be screened in Cannes can be considered a miracle, made possible only thanks to an extraordinary (effort),” she said.

The addition of the extra footage was crucial to the project’s success. “It gives back to the movie its integrity, the way my father wanted and originally edited the movie,” she said.

Gian Luca Farinelli, director of Cineteca di Bologna, says the restoration was far from straightforward.

“The biggest challenge we had to face was respecting the wonderful original photography,” he said. “The story is set in three different decades: each one has been reconstructed to perfection and has three different dominant color tones. We had to be very careful and give back the atmosphere Leone and cinematographer Tonino Delli Colli created for the ’20s, the ’30s and the ’60s.”

Farinelli says the film occupies a pivotal place in the development of American cinema, and had a profound effect on Scorsese, Brian De Palma and Clint Eastwood.

“They had Sergio Leone’s masterpiece as the main reference point,” he said.

Scorsese said the support of partners like Gucci has been critical in allowing the Film Foundation to embark on the restoration of films like this.

“Film restoration is costly, and those costs have increased enormously as digital scanning and processing become the norm,” he said.

Gucci creative director Frida Giannini says that the company shares the Film Foundation’s commitment to craftsmanship, quality and heritage. “Through preservation, the legacy of visionary filmmakers like Sergio Leone, Luchino Visconti and Federico Fellini can continue to inspire us, as well as future generations,” she says.

As well as helping fund restorations with the Film Foundation, Gucci has the Gucci Tribeca Documentary Fund, which offers finishing funds to feature docus that highlight critical issues of social importance around the world.