Minimalistic MK7 with Cleaning Brush

I have made this Minilistic MK7 derived from http://www.thingiverse.com/thing:15718.
I felt that I need to have a cleaning brush inserted to automatically clean the extruder pulley.

Updated 28-03-2013
8mm hole for brush
Updated 29-03-2013
Bottom cut out for stepper motor.
Final.