It is a mystery just how or when Castellano acquired the Kerouac story. According to the company that bought it from his estate, Your Own Museum, it is thought to have originally been given to a San Francisco poet in the beat generation circle. The company said: “It has remained in private hands, meticulously preserved, for over six decades. It is a direct, tangible link to the moment the beat generation exploded into the American consciousness.

Kerouac would often produce typewritten pamphlets and chapbooks – sometimes referred to as ‘brochures’ by his circle of friends. These were not commercial publications but rather personal literary artefacts, gifts from the writer himself, typed by his own hand on his signature long-sheet roll paper and often bound simply.

Subtitled A Brief Tale, the story seems to be a retelling of an episode from On the Road, the first draft of which Kerouac famously wrote in three weeks on one long roll of teletype paper.

The two-page story, described by Your Own Museum as “a quintessential ‘lost’ chapter”, begins: “We hit Denver with the gas gauge kissing empty and the Hudson coughing dust from a thousand desert miles. It was that wild, holy, and crazy time when Dean and I were inseparable, two halves of a lost and found coin, and Marylou was with us, a sad-eyed angel in a too-tight sweater. The money was gone, spent on gas and cheap wine and a wild night in a Tucson motel that ended with a fistfight and a sprint to the car. Now we are broke, the sky was the color of a dirty nickel, and a mean mountain wind cut down Larimer Street.”

The manuscript was discovered by Jerry Braunfield at Your Own Museum, a New York-based company dealing in signed and rare collectible artefacts.

Braunfield said: “We acquired it at the Paul Castellano estate sale in November 2024. It was during this season that his mansion in Long Island, New York was being listed for sale.

“Preceding the sale of the property, the beneficiaries organized a private auction of Castellano’s collection. The amount of time Castellano owned this piece is unknown, however it has never been seen on public records.”

Over the past year Braunfield and his team have been verifying the provenance of the piece, with a third-party company called Proper & Verified carrying out exhaustive checks and testing.

He said: “The short story was bound in the form of a pamphlet. It is two pages long, and the last page is signed by Jack Kerouac. The signature is in green ink, and it shows clear signs of a fountain pen – damp folds in the paper.

“The story itself takes place within the timeline of Kerouac’s masterpiece, On the Road. The dating of this short story shows that it was written during the writing process of On the Road, and it seems to us that it was created by Kerouac for the purpose of him further understanding the setting and characters. Evidently, it was never published, and we find no signs of this work anywhere else.

“Despite it never being authenticated before, the provenance was too substantial for us not to take a risk. To our delight, after lab work and thorough investigation, it was confirmed that the item was from that time. On top of this, the signature was consistent with all confirmed examples of Kerouac.”

Your Own Museum is now offering the manuscript for sale at $8,500.