I admit it has been 56 years, but I remember being taught that the guy closest to the ball goes for it about five yards from him, and the players to his immediate right and left are to cover him and the ball if it gets out. Guess the 9 yard rule thing is a bit different than I've ever heard before.
A good on-side kicker knows which player he is kicking the ball at, and the players beside him do too. So the offense must act fast to offset that advantage.
Oh well, 66 was a long time ago. And since Hurricane didn't win often back then, there were few times we actually got to have an on-side kick made to us (hehe).