Compact Bowden MK7 Extruder 1.75

EDIT 2: After some extensively print sessions, I found that MK7 needs a NEMA17 with 2A coils. The 1A one spkip steps due to high torsion. For those who doesn't have a 2A Stepper, that's the MK8 version: http://www.thingiverse.com/thing:399731
EDIT: it works!!! printed and mounted! New Photos added!
This is a preliminary version of my Bowden MK7 Extruder, suitable for Rostok, Prusa i3, etc.
I derived this from another Bowden extruder for MK8 pulley.
I completely remade it from scratch, is