lantra gearbox

[montesilvia]

im trying to fix my friends lantra whoose automatic gearbox was working for one year with no G/B fluid and eventualy stopped. I have two questions:
- is it better to repair or replace the box? which parts would have suffered inside?
- if anyone is aware of the GEMA(joint engineering group of Mitsubishi, Hyundai and I think Chrysler) do you know if the Mitsubishis that used this engine(G4CN/4G67) would have used the same gearbox as the hyunday?

thank you