I rebuilt my RCS pedals because I hated the center spring and it's pronounced detente as you cross the center, so found them to be kinematically unsatisfactory. I still have my old spring if you want it... Here's an album documenting the mods I did to these pedals, which improved them 100% IMO.
http://imgur.com/a/rnk2TList of mods:
new centering mechanism
precision pivots
replaced pot
felt slides to eliminate scraping
new pedal decks
new shims/reworked pivots for pedal decks and crossbars
Not shown in album is the Combat Pro pedals and fabricated heel rests mounted on top of the decks after ditching the stock plastic foot rests.
I use them plugged into my Cougar still so didn't wire to a new board, but I did make a set of sailplane rudder pedals that still say '
Logitech Attack III' when I plug them into the computer, which doesn't care how a pot gets twiddled.. :p
http://i.imgur.com/yKfrKYR.jpg