The reply I got was to use the longer screw that came with your original lightsaber. I don't have such a screw on my V5 or where it might be. I'm sure lots of people have lost or misplaced screws because the extra screw set is sold out. I'm going to use cording and just tie mine on. It'll look dystopian then.
I actually split up the bundle and I'm using different pieces with different sabers. Very pleased