Former members of the Jefferson Airplane are still fighting to get paid for writing such songs as "White Rabbit" and "Volunteers." Lawyers for the band last week asked a San Francisco Superior Court judge to order the release of about $2 million in royalties that RCA records has held for two decades. RCA lawyers told Judge Ollie Marie-Victoire that the company would gladly pay the band--if she would dismiss an old lawsuit brought by the band's first manager, Matthew Katz. "What I can't understand," Marie-Victoire said, "is why this lawsuit hasn't been dismissed before. The case is 20 years old."