Well, honestly, I don't think it needs a technological solution. If you can actually manually add these features into the track without screwing-up the rest of your work, then an "eyeball" approximation is sufficient. There will be next to no people who have actually driven the track in real life using it, so we won't know if it's accurate down to the centimetre or not. But everyone will benefit from some close approximation to the slope, camber and track surface improvements (including the curb surfaces and traction level).
There are many fictional tracks that nail these qualities just because they seem real and appropriate for the surroundings. This track is fairly flat compared to many others, so the change will be minimal overall, but you and I know that a hairpin curve with a 2% camber gradient is way different (and more fun) than a perfectly flat one. It's what makes outdoor kart tracks so much better than the industrial warehouse-style indoor tracks with their perfectly flat concrete floors. If you have access to the track in real life, I think you could get us 95%+ accuracy with these simple measurements and then some intelligent tweaking:
1) The total elevation difference from the highest position on the track to the lowest (the track owner may have a plan that shows this, or you'll have to just do your best to estimate if you don't have professional surveyor equipment and technique (joking))
2) Take an accurate level (could be a metre stick combined with a smart phone level app) and estimate the camber of each corner
That's it! If these are not possible because the owner won't let you or doesn't know about this project, then just "eyeball" it (meaning just use your best estimate).
If the owner doesn't know, you should consider seeking permission and co-operation. If I were them, I would hopefully realize that I had zero chance of getting any licencing fees for my little track "in the middle of nowhere," but also recognize that I was getting some free publicity. There will be some of us rF2 fans who would seek out the track if we were visiting the area, but who otherwise would never know that it existed! I would supply you with the official logo, etc., AND give you as much free track time/kart rental as I could afford.