Electrolytics will almost certainly need done. It may play for a while with the originals but not long. I wouldn't worry about film, ceramic or mica caps as those are almost never found to be bad if they pass a visual inspection. Those older plastic encapsulated carbon film resistors can go bad. They usually drift up in resistance depending on use (more is worse unlike electrolytic caps) and storage conditions (heat is bad). Humidity is also but if the resistor case is degraded enough to allow moisture, it will simply burn up very quickly. It's possible that it has a selenium rectifier too given the size of the filtering cap. 70's is a bit late for one of those though. Then again it wasn't the era of JIT logistics and it was common for manufacturers to stock years worth of components and use them until supply was exhausted and redesign the rectifier circuit only when necessary.