Radiator pressure test

Not a scam with a 50-60 year old core. The cores are made of a much thinner gauge of material and suffer the most from heat and corrosion. Just remember that the radiator is only a part of the complete cooling system and if the cooling system has not seen regular service/maintenance you can also need some or all core plugs, heater/radiator/by-pass hoses, clamps, water pump, thermo-stat, definitely a new radiator cap as well. Proper mix of correct type coolant and distilled water.
No different than going to the Dentist after having not gone for many years. Expect some cavities...