A couple of notes for this thread, starting here:
This can be updated using a flash tuner like a Dynojet PowerVision or TTS MasterTune.
You only need to prove that you rode the distance required of the ride. If your odo is off, note that and ride the required amount. Documentation from the GPS and/or other mapping is acceptable, as long as you can prove that you rode the required amount. Your odometer reading can be used to prove consistency, if not accuracy for your ride.
Many thanks for the advice, I am still in the planning stage right now, but I need to know where I am going, this helped me out a lot, I have been advised that I need to use my odometer to show the distance I have ridden, and that worried me a bit, that is why I have asked, I had no idea how the speedo is done being electronic and my knowledge is rather limited and therefore at the mercy of those in workshops. If this can be changed by a tuner then maybe I could look into getting one. maybe I already have one and don't realize it yet I will find out tomorrow, once again thank you.