The most difficult part of the process was gluing the layers together without causing any hazing or dis-coloring of the water effects plastic. This was ultimately accomplished with Model Masters Airplane Canopy Cement around the edges. It worked exactly as I wanted and caused absolutely no discoloration. I then ran a bead of clear RTV silicone around the edge to hold it in place inside the gate when it was popped in. I originally intended to use magnets but this proved nearly impossible and good old friction ended up being the better choice.
Now I just have to make a dial home device of somekind and I'll be set.