Condensor is in front of the radiator. The evaporator is the unit that exchanges heat from cabin.
I would strongly suggest that you verify the leak location before replacing anything. The evaporators are a source of problems, but don't replace it because that historically leaks on this car.
I would suggest using UV dye and a UV light to ENSURE the location of the leak before doing anything else. If you cannot get access to UV detection equipment, try to find a "sniffer".
This being an R12 system makes it even more important to know that you're fixing the leak. You don't want to "cut and try" with the current R12 prices being what they are.