PN 3  PHOENIX, Ariz., June 19 - AN AMERICAN NOW - John Richard Booth Jr., 15, and his adoptive and bachelor father, T. Sgt. John R. Booth, look over the papers which officially made the younger Booth an American yesterday.  The elder Booth, now an Air Force recruiter, salvaged the Korean War orphan in the backwash of war seven years ago.  Now that he is a citizen, the younger Booth hopes to follow in his Dad's path by getting an appointment to the Air Force Academy.  (AP Wirephoto) (dwc31645gaz)  '62