I have the dealer looking it up to see what it would cost, etc. They weren't too sure exactly which part, or if it was a sales part. Hopefully they'll get it figured out.
If not, I may have to go the other route and run the line from the PB port on the joystick like you mentioned. It's really not an issue since it would just follow the existing lines that are already there if I had to go that route.
Then I have to find some receptacles or connections with mounting plate to mount it somewhere on the back.