SAIGON ASSEMBLY CONSIDERS GIVING MINH LEADERSHIP
S Vietnamese Pros Tran Van Huong calls on Natl Assembly to decide whether to replace him with Gen Duong Van Minh in order to negotiate with Communists, Apr 26 speech; says he cannot turn over power to Minh himself because it would be unconst; assembly begins emergency session following Huong's remarks; Vietcong spokesman Lt Col Vo Dong Giang comments on recent attempts by US officials to change pol structure of S Vietnamese Govt to conform with Vietcong demands; Vietcong officials deny they are demanding that any particular person head new Saigon Govt, series of phone conversations with NY Times; recent activities of former Premier Nguyen Cao Ky, natl labor leader Tran Quoc Buu and Buddhist leader Thich Tri Quang noted; Huong and Ky illus (L)