He was groomed from the age of 11 by Bolton, who would tell him when fondling him that this was what fathers did to sons.
Mr Endelman, 54, said he was motivated to produce the film to try to encourage men who had experienced similar abuse to speak about it rather than keep it under wraps.
Giving evidence at Bolton’s trial, in 2015, he described how he had later been ashamed about what had been done to him as a boy but had not revealed it to his parents until 20 years later.
As well as the film, Mr Endelman is planning a documentary and the launch of a foundation, the Consent Project, which, he said, “will allow men, boys, young men to talk about what happened to them and really get it off their chest and to figure out how it’s affected their lives”. In his own case, he is convinced the stress of repressing his abuse for so many years caused the rare form of brain cancer that left him in a three-month coma seven years ago.
The title of the screenplay, which has been co-written with a friend Adam Matalon, alludes to his childhood. “When I was a child, from the age of about eight, I was fascinated with this big red box kite which my stepfather and I would fly in Dorset, as high as you could imagine,” he said, “It became the symbol for me of freedom and it still is.”
Bolton, who befriended homesick and vulnerable boys at the college, was once invited by Mr Endelman’s family to join them for a holiday in the south of England. “Bolton did come to Dorset and [he] did fly the kite,” Mr Endelman recalled.
The composer, who wrote the score for Rober De Niro’s first film as a director, A Bronx Tale, has been raising money to finance his project.
“We have our casting director,” he said. “We are going to start shooting on January 5 next year.” He hopes it will be ready for screening in the spring.
While the film will not identify the scene of the crimes as Carmel, he said: “We will show it is a Jewish school” because it is important to show that abuse is “pervasive” within all communities.
