I can't stop tinkering, and working on other ideas.
I was worried that overuse of my current design could eventually lead to a loose screen, so I have been working on a design that is thin enough to slide through under the screen. I'll post a pic when the design looks good, but until then, I thought I'd share some diagrams i am working on for these next "thin" prototypes.
I wanted clear plastic to work with, and one with curve already in it as to slide around the phone edges, so I am using plastic from packaging, like in this instance, the plastic packaging around a ping pong paddle. Also, I am no longer using original buttons, I have laid a thin piece of rubber on the back of the gamepad and created buttons on top, its much easier to reproduce and the added plus is a mush more aesthetic look. Pics up soon, but until then if you want the original Adobe Illustrator PDFs to work with and edit as well, download here.
Hope this helps a little!