What I have learned is that in '71 the tubular rims for the P-13-9 stock were generally either Weinmann hollow or Weinmann wood-filled. They did not go to the Schwinn Approved until 1973 or so, so these are not exactly accurate, though in my opinion highly appropriate. Another interesting thing is the Schwinn Approved are actually Super Champions, rebadged. I think these in particular were based on the SC Record du Monde, which are 330s. I have also seen Schwinn Approved 260s....