I cut and fit a piece of aluminum for the far left side of the front wall of the compartment near the spar channel to fill in the space in order to enclose the compartment.
Next I worked on getting the final outboard bottom angle cut and fit. The front of the angle is being supported by the support that is connected to the spar channel. For the rear I made a bracket out of 1/16 angle. Because the bulkhead for the rear attachment point is not perpendicular in the fuselage, I had to tweak the angle of the aluminum to fit. Not quite there yet.
Gap fill piece for left side of compartment
Final support angle for outboard compartment bottom