BUENOS AIRES (AP).- The protectors of Marilyn Monroe’s image say a collector who wants $500,000 for a short 1940s stag film is committing fraud and violating the actress’s intellectual property rights by claiming it shows her having sex when she was underage. Mikel Barsa, a Spanish events promoter, insists that the scratchy, black-and-white six-minute film shows the young actress, known then as Norma Jeane Baker, around 1946 or 1947 when she was poor and desperate to break into show business. Experts on Monroe’s life, however, say it’s highly unlikely that the smiling young blonde in the film is her. Comparing the film with known Monroe images leaves ample room for doubt. Also, while Barsa shows off various documents he says support his theory, they self-evidently fall short of proof. Whoever the woman