Re: ARC-AAA tandom tube: comming soon
Sheesh - you don't want much, do you dilettante?
What you're asking for is pretty tough to make, since it can't be made on the lathe. If I were you, I'd epoxy my three Arcs together, screw a pocket clip into the middle lanyard hole and call it a day.
What you want could certainly be made on a CNC mill, but it will be way more involved than something round and threaded.