A lost world of Disney is to be made public for the first time, including images that, when added together, show Donald Duck dancing with giant cigars, and sketches for a film about the American folk hero Davy Crockett.

Film historian Daniel Kothenschulte has collated celluloid images from hundreds of Disney projects that, for various reasons, never saw the light of day. Having been given unrestricted access to the Disney Archives and Animation Research Library, his discoveries are to appear in a major book entitled The Walt Disney Film Archives: The Animated Movies 1921–1968.

Kothenschulte told the Observer: “You open up pastel drawings that are still rolled up, and all this coloured dust appears on the table. A wonderful moment. The Donald Duck film was developed pretty far. There are beautiful colour storyboards, pastels that give you a view of the whole film. Those have never been published anywhere.”

Kothenschulte was also given access for the first time to Thomas Hart Benton’s 10-page treatment for a never-made Davy Crockett film, with sketches of “fantastic” swamp creatures drawn in 1946. “This is a wonderful thing that nobody has ever seen except for the archivists at Disney,” he said. “It’s not just the images that have never been seen; nobody knew what it was about. It was just known that a Davy Crockett project was in development.”

In the book he writes: “Benton shows himself here as a true storyteller who uses the opportunity to pay homage to his second-greatest artistic passion – early American folk music. The script begins … in a swamp landscape, out of which alligators emerge and begin to tap dance to Johnnie Queen’s Clog. The song grows wilder and wilder as the alligators transform into ‘ring-tailed roarers’. In a sketch, Benton depicts one of these creatures out of American folklore, which he describes as ‘half-alligator, half-horse, and half-devil’.”

Speculating on why the project was shelved, Kothenschulte pointed to a letter from Benton that suggests it was too extravagant, although Disney himself was an enthusiastic backer. Other ideas that fell by the wayside include a feature film on Hiawatha, inspired by Henry Wadsworth Longfellow’s epic poem, The Song of Hiawatha. Kothenschulte described the surviving storyboard as “monumental”. Other unpublished imagery includes a scene from the short film, Little Hiawatha, in which the main character’s canoe is wrecked on forbidding rocks.

The holdings of the Animation Research Library extend to some six million artefacts, of which Kothenschulte estimates “less than a million have been scanned or catalogued so far. I was able to get access to things that other scholars didn’t, or maybe they didn’t ask the right questions. It’s not an archive that you can just move in and touch things. You have to wait for them to come up with a box, or maybe 10 boxes if you’re lucky.”

With 1,500 illustrations and essays by Disney experts, the book covers each of the major animated films made in Disney’s lifetime, including Snow White and the Seven Dwarfs and The Jungle Book. Kothenschulte said: “With every film, we have examples that have not been published before. We have 50 or 60 unpublished drawings from The Jungle Book.”

He also expressed excitement about seeing beautiful storyboard illustrations of planned extensions to Disney’s musical masterpiece Fantasia: “None of this was made into a film. This was my greatest joy to see.” Single images have appeared in print, but the whole sequence has not. But he added: “It’s also disappointing to see what they don’t have any more. In the past, they didn’t see a purpose in saving cels [celluloids] and backgrounds, so they would discard or sell them.”

Kothenschulte is also publishing the full transcripts of story conferences held by Disney with his staff. “This is something very rare,” said Kothenschulte. “Other studios don’t have this. Walt Disney liked to have everything documented. He had stenographers present during all these story meetings, which could go on for hours, just making up ideas.

“Walt was the key story man, as you can see, but everyone had an opinion. It was a very open discussion.”

The book’s introduction is by John Lasseter, the Oscar-winning director of Toy Story, the world’s first feature-length computer-animated film. Lasseter, who is now Disney’s chief creative officer: “People sometimes describe something as ‘Disney’ as if it were a single look and style, when in truth the look of the studio’s work was continuously evolving.”

The Walt Disney Film Archives: The Animated Movies 1921–1968 will be published by Taschen on 1 October