Short answers, pulled from the story.
Lee Eastman, born Leopold Vail Epstein on the 12th of January 1910, was an American show business lawyer and art collector from New York City. He is best known as the father of Linda McCartney, as the business manager who guided Paul McCartney's solo career and music publishing investments, and as a friend and longtime lawyer for abstract expressionist painter Willem de Kooning.
McCartney wanted Eastman to manage Apple Corps and the Beatles' careers in early 1969, but he was outvoted 3 to 1. John Lennon favoured Klein, impressed that Klein knew Lennon's lyrics and calling him very intelligent; George Harrison and Ringo Starr sided with Lennon.
Eastman advised McCartney to invest in music rather than unfamiliar industries, then asked which artists McCartney loved most. When McCartney named Buddy Holly first, Eastman located the owner of Holly's publishing catalogue and purchased it for McCartney, launching his music publishing business. By 1984, McCartney estimated that half his income came from his publishing holdings.
For a short period in 1969, Klein managed Apple Corps and the personal careers of Lennon, Harrison, and Starr while Eastman served as corporate counsel and managed McCartney. The arrangement collapsed after a contentious meeting, and Eastman was removed. Klein later left Apple Corps himself following a series of suits and countersuits, taking a multimillion-dollar buyout.
Lee Eastman died on the 30th of July 1991, of a stroke, in a New York City hospital. He was 81 years old.
Through his daughter Linda McCartney, Lee Eastman is the maternal grandfather of potter Heather McCartney, photographer Mary McCartney, fashion designer Stella McCartney, and musician and sculptor James McCartney.