The absolute "best way" to deal with rust is to disassemble the car, have it media blasted, or acid-dipped, then immediately
Be sure to drive it enough so that you can get a feel for how the car brakes, turns, accelerates, and idles.
However, remember that there are many conditions which can impact the value of your car, especially the condition of the car in question.
The statements expressed above are only for informational purposes and should be independently verified.
Need Help With Your Car?
What I suggest you do is weigh the cost of the repairs
Parts For Sale.
Take note of the following:
Other Collector Vehicles For Sale.
Make sure that the engine runs.
The dipstick will normally have a curved loop that you can use to pull the dipstick out.
Checking this vehicle's history could be a very difficult task since you are seeking information from another country.