This remix of the HGA allows it to be printed without supports. The HGA is cut into two parts and the flat sides should be oriented towards the print bed. They should be either screwed together or glued together. You can make them seamless using filler and sanding, and the seam can even further be covered up by creating the fake "weld" over the joint. This can be done by putting a thick, uneven, weld-looking line of hot glue around the edge to make it look like the welding in the original prop, as seen in this image.
Amazon Basics PETG
These are just the settings I used to print this out, there are plenty of other settings that can be used to successfully print this part.