Couldnt find one I liked or could print so knocked this up on Tinkercad.

:( Havent been able to print yet - my luminous blue PLA is being a real beach! This is worth sharing - got a tip from RepRap Forum; print the glow in the dark on a 60deg bed instead of usual 85deg. Made helluva difference.

I've added an image and had problem with window frames when I printed at 50%. So gonna have a tinker with it!

I redesigned as a kit; http://www.thingiverse.com/thing:106519