CTC / Flashforge: 1/4" Glass plate holder

I wanted to print on a glass plate with my CTC Dual as I had torn the 'stock' Kapton tape that they had pre-installed on the aluminum heated bed. I liked 4KoeTTer's design, but living in the US, I can't get the Metric picture frame glass that he designed it for, and I didn't like the idea of using just 2mm thick glass anyways. So I decided to use a thicker glass that's readily available in the USA. I chose 1/4" thick (approx 4mm) 12in square mirror tiles from Home Depot, which I cut down to t