the PRR classed the coaches based on the length BETWEEN the vestibules, so a P70 (70 ft coach) is 70 feet plus the vestibules which makes it a scale 80 feet or so when you at those at each end. It is basically a "Paired window" coach, so it should be close for any road that used that type of window arrangement.
Paired window means each pair of windows has a narrow vertical post between them, and then each pair has a wider post separating them from the next pair. A number of roads had this style, B&O comes to mind as one.
