If you look closely at the inside of the neck area on the chest plate, there is a metal D-ring attached. I'm going to try a hook-and-eyelet method this time, especially since the red striped parts allow the chest plate to just rest on the shoulders while the backpack locks into place in the indent. The actual shoulder pieces, waist "ribs" and crazy wrist parts I'm still undecided on. I could always just use the easy method and do a combination of gluing parts to the bodysuit and industrial strength Velcro like I did with the Rei.

The current plan is a type of patented leather. I own a stretch vinyl Asuka plugsuit that doesn't agree with me much and the original zentai-suit-based Mari is a little too flimsy.