Match speedometer status with change or repair?

Hello, since I am thinking of changing the instrument that has not been functioning since the last days… or at least repairing all non-functioning things… I wonder if I can restore the function of the odometer/kilometre meter that died at a stand of 285,000 km. Is it safe to be mechanical with my 92er Avant. There are still a number of lights to change and I finally wanted to take an afternoon time. If the thing is not reparable… and I can shoot a cheap part in the bay, I would like to bring its km stand to mine, which should be at 330,000. I just want to avoid that if I sell it once SOLLTE… then I would need to find an AI with approximately similar km stand. Before the whimper goes off… I don’t want to sell the car or change the km stand to the bottom. I just want to avoid that if I sell it once SOLLTE… then the tachostand of a whole KI to the stone of stumbling. Will but also not have a part to repair with 45 km?