Groin and Waist mod. I decided to use the Exia's groin and waist assembly mainly because it's more flexible and articulated than the 00's. As I have mentioned time again, the 00's construction is so poorly designed it's more of a downgrade from the Exia in terms of detail and articulation. I was quite disappointed with the 00's simplicity after having seen the Exia's close to MG pseudo frame.
I started with the main groin assembly by cutting the top portion off and extending that with plaplates reinforced with small pieces of 3mm beams. Note that I filed the edge of the plaplates at an angle so it can fit snugly onto the crevice, providing a greater bonding area and thus a stronger bond overall.
I've modified the Exia's waist adapter, trimming all the unnecessary parts and cemented the "nape" mod to it.