Malbert J. Caplan, 77, a former MGM costumer and a trustee of the Motion Picture and Television Fund for nearly 15 years. Caplan began his career in costuming in 1937, handling most of the Abbott and Costello films, and served as MGM's executive in charge of the costume department from 1951 to 1969. He was administrator of the Motion Picture Health and Welfare Fund (now called the Motion Picture Industry Pension and Health Plans) from 1970 to 1990. He also chaired the fund's Heartbeat of Hollywood Golf Tournament since it began 16 years ago. The tournament raised more than $500,000 for retirement cottages, equipment, supplies and renovation of the employee cafeteria at the Motion Picture and Television Hospital in Woodland Hills. On Sunday in Woodland Hills.