After a long period of neglect, i've gotten inspired again... made a lot of progress today, and I'm taking a break. Might actually finish this tonight...
Still wasn't exactly sure how, but I wanted to avoid dismounting the joystick boards... a sudden brainstorm occurred. Ran the base through a bandsaw to get rid of the legs, and cut the center tube (which holds the rudder pot) one more time so I could slip it onto its original shaft so that the pot is just peeking out.
Then I hooked up the modded controller to my PC, fired up FS9, changed my control assignments, so now...
I control rudder with the Logitech pot:
...and I'll solder the leads from the doorbell switches on the pedals to these two buttons to control brakes. I was delighted to find that pushing both of these at more or less the same time produced a good result; I was worried I'd still have to use another button for when I want to hit both brakes simultaneously.
The base will be mounted upside down with brackets, in such a way that the pot will be manipulated by tabs attached to the center of the center crossbar.
Next: some views of the entire unit