Something else you could try Bob is "nano tape". It's a reasonably thick clear plastic tape, which is sticky (without adhesive) but peels off easily. The claims seem magical, but I'm using it to stick signs to walls etc, and it should just peel off.
It *looks* optically clear, and a small piece in each corner would work like bumper dots but would hold the glass on pretty darned well.
Lots of suppliers on ebay etc. (but no guarantees about delivery to Cyprus!).