Gregorio (Gringo) Honasan, leader of the failed 1989 coup against Philippine President Corazan Aquino, may soon turn himself in, Western diplomats in Manila say. The Aquino government recently freed more than 60 military officers jailed for allegedly plotting against Aquino. Honasan demanded the releases as a condition of his surrender. Now, the sources say, the fugitive ex-Army colonel is discussing the terms under which he will give himself up. Honasan's surrender would be a propaganda victory for Aquino-the target of numerous coup attempts--despite the high number of former rebels back in circulation.