How would that work from the left side? You have the swivel bar there. And if you only have the brackets at the very top and bottom I don't think it would be very secure. On the right side you also have to make sure that the brackets are not too deep, after all, the bezel of the 800 is very small. Better do some thorough research, or it won't work very well.
Other than that, it looks quite good. And you would need a pen holder, inside the the cover, preferably. Also remember, the European pen is thicker than the US pen. You could use brackets on the right, top and bottom. That might work well, just sliding the device in from the left. However, make sure to leave the power button and micro USB port at the bottom left uncovered. Those clear brackets would probably look ok with the Irex 800.
Using a very crude ruler (not a gauge) I measure 14.8 cm left to right, 19.2 top to bottom. The bezel is 1.5cm top, left, and bottom -- but only 1.1 on the right (meaning the bracket on the right would have to be quite small. Overall thickness is about 1cm. I am sure you can get the exact measurements off the Irex website.