ive been looking into this a bit for my 90 ali
the popular concensus for a reasonably lasting repair (but not perminant)
is - wirewheel - if you have any door left, vinegar soak - if you have any door left , etch primer/sinc chromate , p38 back to surface level then high build primer /paint
annoyingly alot of the time it is either rotten through from inside or galvanic corrosion from being in contact with the steel.
tiger seal/DPC between seems to be another popular route against that.
not 100% on my final route yet but you can look that up while you enjoy Romania.