What Eric said plus,
attach the chest to the ab piece with straps and snap plates and do the same with the kidney and back armor. This will keep the parts where they belong and spaced correctly, then you can make adjustments to the chest and back straps.
Being taller like you,I got the chest piece to overlap the ab by 1" or so, just enough to keep it in place. Use elastic that is woven in two direction, the elastic that comes with the kit is to wimpy and tends to stretch to far. Most fabric stores will have this in stock.
I used a heat gun to bend the butt piece so it fit better between the legs, and didn't hang down so far. You may not have to do this.
The bells will sit better by installing another snap more foreword on the chest and back strap. You look really good, just a few adjustments and your there.