A rotted radiator support along with the inner fender and battery box is pretty common. Especially here in the NE. Unfortunately it's not a job that most do-it yourselfers can handle unless you have supreme welding and fabrication skills. I would also check the inner rocker panels and behind the splash shields. Usually if the car is that far gone those areas will also be rusted through. As far as the radiator goes the core itself may be fine. It may just be the mounting bracket that's rusted. However since it's been sitting since 1993 It's only a matter of time until it starts to leak. I would look for another one or have it recored and repaired. Hopefully you didn't pay too much for the car as it sounds like it needs extensive rust repair. If you can't do the sheet metal work yourself you'll wind up putting far more into the car than it's worth.