Hoplite,
In 1C Forum you find Artist, that did this, wire G-940 pedal, throttle and
rotaries to one BU0836 - to overcome reverse axis bug.
If you plan to use G940 pedal standalone, I think these Leo Bodnar board is fine:
http://leobodnar.com/products/DFPG25conn/Primary intend for G25/27 pedal, but fine to aircraft rudder pedal too.
Is just a 3 axis controller.
To map DB9 pinout is easy take a multimeter, open pedal base and test DB9 pins with pots contacts.
Sokol1