I have owned several cars with radiators that started to leak around 200,000 miles. Typically, the leak was from the crimped edge where the metal meets the plastic side tanks. There is a rubber gasket in there, which simply wears out from repeated heating/cooling cycles.
Also, while doing routine maintenance, such as replacing the radiator hoses and heater hoses on an old car, it is very common to discover that the plastic fittings on the radiator have deteriorated–especially the upper hose connection. The plastic becomes discolored and soft, and pieces of it break off, or sometimes the entire fitting breaks off when attempting to remove the hose.
I would definitely replace the radiator, radiator hoses, heater hoses, water pump, and thermostat on this vehicle–using only quality brand-name parts. For aftermarket radiators, there’s only one brand I trust–Denso First Time Fit. And as always, you can get these parts online from Rock Auto for less than half of what you’d pay in a big-box auto parts store.