The main bulkheads in this kit are square on top, so they are flush with the top of the fuselage sides. This allows the fuselage to be built upside down on the table. There are also arched bulkheads to go on top of the lower bulkheads. #3 is the instrument panel and is installed leaning forward.
The kit can be ordered with standard ribs. In this case you build the wings and cut the ailerons loose as shown on the plan. Or you can order the alternate ribs, which are cut short. The stick at the trailing edge of the ribs is 1/4″ balsa, and the aileron is 1/2″ x 1.25″ balsa trailing edge.
I’m guessing that you’re interested in building this plane because of the super cool looking cockpit. That’s what caught my eye. The kit includes three bulkheads for the rear deck, but there are no parts included for the top deck or cockpit between the instrument panel and the trailing edge, so you’ll have to figure out how to build that super cool cockpit yourself.