UPDATE2: added a better LCD screen that fits nicer.
UPDATE: I've added a version with pegs to hold it in place. The pegs have been cut flat so they should stick to the build plate better. You will still need glue but it helps hold it in the perfect place.
Peg Version: Peg_Flat_Bottom, Body_Mod_01_Cut1&2
Glue only version: Body_Cut1&2
The original body was too large for my Duplicator i3 so I cut it into two pieces that can be printed to fit smaller build plates of 200mm. Portal Gun can be found here: http://www.thingiverse.com/thing:1100601
If your printer is good at overhands it should be able to print the handle part without any supports, but the main body will still need some.
NOTE: I haven't tried printing this yet but will do in the next few weeks, if you print it please provide some feedback/pics for others.