UPDATE: Added a fixed file.
This is a remake of the THING: http://www.thingiverse.com/thing:547706
I really liked this design, but ther was no *.STEP file to make changes to the original design. I've printed one and using a caliper, measured and draw this model on FreeCAD. The sources are available for download.
14/02/2017: Files uploaded.
15/02/2017: Version 3 of the extruder holder uploaded. There was a disaligment at one spot of the design. Version 3 fixes that.