Good stuff.
The "boxes" behind the pilot's seat are the H2s indicator and receiver, on their swinging stanchion mount, and were not fitted to your subject aircraft.
Those aircraft with H2s had a large blister beneath the rear fuselage, an the viewing blister on the port side of the cockpit windows would be deleted.
The "box" at the navigator's table is the "Gee" indicator, a navigation aid, and most likely would be present. The radios are aft of this, in the radio operator's position.
Even in larger scales, not much aft of the main cockpit can be seen through the glazing, so don't worry too much about detail in these areas.