I bought the actual two-way mirror three days ago and have been kicking away at setting up the actual Raspberry Pi for showing the screen. I got a whole 2'x4' sheet of it which is cut down to 11"x18". Two-way mirrors are actually like acrylic plastic, so they are cut in the same way. I had mine cut by the shop that sold it to me, since it was just a simple rectangle. I have to get some foam adhesive strips to mount the plastic to the LCD now.