I would say, start with plotting out the size of the cab based on what we see in RotJ, and then try to line up the specs to that. Unless you can find a specific size of the original life size prop but then I don't know how much of that was built considering a lot of times they'll just build what they need for the film.
The only reason I say is it's going to be hard to get a correct scale when there are times in RotJ where they look huge and times when they look small and that just comes from the animation. Someone saying 8.2 meters doesn't necessarily mean squat if that's just the number someone threw out for a fictional technical manual.