This project is not dead. A lot has happened since I last posted (most notably a new baby!), but I've recently obtained access to a 3D printer. I've wanted to print the throttle for my controller, so that seemed like an obvious choice to print it. After a couple of prototypes and a couple of redesigns, it's coming along nicely. It's a 7 part build that includes a chassis, a cover, two control arms, a handle and two end caps. The Vex potentiometer fits right onto struts I built into the chassis, so it's mostly tool-less.
I'm still waiting on one part and I have to re-print the handle with a bit more spacing. After that I might take a crack at printing the body panels for the console rather than trying to cut plexiglass.
Many thanks to Josh who provided access to the 3D printer, help with fixing my models, advice on printing and the idea to use two arms.