There seems to be a difference between plans and video regarding the position of the air inlet at the pressure box. Which is correct ?
A. The original plans showed the air entry to the pressure box, at the bottom of the box. JS altered the later plans to show the air entry on the drive wheel side, adjacent to the feed spool holder. The change was made so that the air feed pipe didn’t have to turn through 90 degrees. In fact, you can put the air feed anywhere in the pressure box so long as it doesn’t interfere with any of the mechanics.