LOOKING BACK • Undersecretary of State, Joseph J. Sisco, retiring after 25 years in the State Department, is honored at a 1976 luncheon sponsored by the Conference of Presidents of Major Jewish Organizations.  Left to right: Rabbi Alexander M. Schindler, chairman of the Presidents Conference; Mrs. Sisco; Secretary Sisco; Israeli Ambassador Simcha Dinitz, who praised Sisco as a “true friend of Israel;” and Yehuda Hellman, executive director of the Presidents Conference.