Dating from December 1969, the document features blue, black and red writing with cuts, revisions, notes and rough sketches of shots.
It also includes a note of congratulations signed by Bryan Forbes, then head of production at the EMI film studio, and a letter from a relation of Nesbit.
Also included in the lot is Jeffries’ personal copy of the novel, which is also extensively annotated, including a list of characters and casting possibilities.
The Railway Children told the story of Mrs Waterbury and her three children, who move to the Yorkshire countryside after their father Charles is falsely imprisoned.
The film also starred Dinah Sheridan, Bernard Cribbins, Sally Thomsett and Gary Warren.
The collection includes a prop railway workman’s lamp, a prop red despatch box marked as being from the Foreign Office and belonging to Charles, and cabinet card photographs of the Waterburys and their London home.
They feature in the sale of 19th and 20th century books and manuscripts at Sotheby’s, ending on Tuesday December 14.