Here's a test fit of the waist assembly.

A iittle bit more detailing, panel lines and 'EPPT'.

The lower torso section was also detailed with some 'EPPT'. The front portion was intentionally not assembled fully to create a gap, which adds to the details for the entire section.

The hips originally had an exposed PC joint which I cut away and covered up with a minus mold. To avoid the outer armour from scratching the minus mold, I cut away some of the plastic around the edges as shown below.

Here's a test fit of how everything fits together.

Some more panel lines.