Entertainment Attorney Michael Koskoff is being courted by Hollywood. The 74-year-old litigator is a first-time screenwriter with “Marshall,” a new film about the late Supreme Court Justice Thurgood Marshall, out Friday. Even more overwhelming for the man who boasts a 50-year background fighting criminal and civil-rights cases, was the experience of screening his movie last week for retired justice Sandra Day O’Connor. “Surprisingly, to me, [she] was very close to Thurgood Marshall,” Koskoff tells The Post. “She said that he, more than once, was the person who swayed her to change her mind [on important votes] — with his stories.” Koskoff and Marshall, who died in 1993, have storytelling in common. Nine years ago, a friend approached the Bridgeport, Conn.-based lawyer with an intriguing and little-known case he’d been researching: the 1940 trial of Joseph Spell, a black chauffeur who was charged with raping his employer, a white socialite, in nearby Greenwich. Spell’s lawyers? A young Marshall and Samuel Friedman, a Jew. “It was a great bond between an African-American and a Jewish guy at a time in history when both were subject to a lot of discrimination,” says Koskoff. “There was this great commonality of cause that I, […]