My version of the multi used Single Point Scope, which is part of a lot of Star Wars Blasters.
It is designed so you can put a 3mm acrylic rod in the center, probably a Lego Red Light saber will work, haven't tried yet though.
The Scope rings mounts with some modifications were remixed from this great piece:
Enjoy, I've already printed it, with no issues!!
This is my second print of the Scope, the first was with a black front tip, but the second I want the front tip to be transparent, but I have not figure it out how!
The red rod, is a Lego lightsaber or antenna that I've bought on a flea market!!