Might have to repaint those lines there kind of shaky. The cover strip on back thigh has some gaps may need to be re done. I'm not to sharp on the e11 details. You already addressed the butt plate issue. Think you are on the right track Jason.
Here's how mine looks now. Just Velcro and used a little strap to help hold it on also. I will eventually tighten the tube up. There is Velcro behind the Icomm and the amp.
I need to go get a new mask. Did you notice the black ABS gets a lot hotter and smokes more then the white ABS plastic does. I had to stop because of the fumes.