Maybe I'm being paranoid, but let's see if kramstar is okay with it being in the guide first.
I think the tube on the Vader Stunt is one piece with a separate should collar onto it. Held to the tube with that set screw on the flat face. It's a very simple but beautiful saber. The 4 Allen bolts, though probably post ANH, make it cooler in my opinion. You can also see the core has two sections that split behind the empty screw holes up top