I started making a deep extension to the bulkhead closeout panel in case I want to carry light but long things inside the fuselage. Later I will construct a removable plug to prevent unwanted items from falling into the space and upsetting the CofG, but it should be handy space for fishing rods etc.
The braces and box need to be fitted with platenuts so it can be installed aft of the closeout panel, which is aft of the bulkhead.