VENICE, Italy — Of all the roles Ellen Burstyn might have been offered in her 90s, that of Marilyn Monroe seemed fairly unlikely. But then one day Maggie Gyllenhaal came to her apartment to talk about a wild idea: What if she played Monroe at 100? "It sounded like a good idea to me," Burstyn told The Associated Press. Their 17-minute short film, Flesh Impact, had its world premiere Monday (Sept 7) at the Venice Film Festival, where Burstyn, 93, also received a Golden Lion for Lifetime Achievement. Ellen Burstyn's Marilyn Monroe moment Though Burstyn never met Monroe, who died at 36, there was overlap. They shared a massage therapist, who…