This is the DT-12, Greedo's Blaster, (Brand new; never been fired) as seen in the cantina scene in Star Wars ANH.
I've make this for a Friend in the 501st. the base of the weapon is the Ruger Mark III, wich I found here:
I've make some arrangements to that model in order to make it easier to print, the rest of the parts was designed based on several pictures I've found, I think scale is correct, but please check this out.
There's a piece called Merr Sonn 5 twinky and Merr Son power 5 disk, you only need one twinky and two imperial disks, although the files has 5 pieces each.
The Handle is complete or in two halves, depend on you.
There's also two versions of the stylus
Update: August 6th. 2017
I've uploaded a picture to help assemble the safety group, and an alternate version of the antenna or sight pins.