Well guys (and gals), today is your lucky day: my junkyard odometer gear sheared its teeth early January and I've just got around to replacing it.
Between my all my rambling, it managed to stretch the video to 30 minutes so get a cup of your favourite beverage in advance; however, if you only wish to know about the electronic rolling forward of the mileage, I'm pretty sure it's only the second half of the video.
But yeah, it (should be) live now at the following link, so enjoy.
https://youtu.be/sBc2NeJ9_BQ