Picture 1 is another "reward" step - pushing in snap bushings. The lower part of the picture is the step bulkhead. The seat bulkhead is above and behind it. Retrospective Note: If you intend to paint the interior you will probably want to remove these grommets again. You may also need to remove some of them when you install the fuel lines. Consider not installing them at this stage.
And Picture 2 is a confusing picture of the steps section of the fuselage looking from the bottom. It's not a set of shelves! There's no floor over the centre compartment so you can see the garage door hardware through the hole ;-)
