You will need to at least test the reisistor with an ohm meter (dmm or whatever has an ohms function!) to try and see if it has a sensible value or is open circuit. Being a power resistor I would say its value will be on the lower side. Do you know someone who has a dmm ?, who can check for you. (Im guessing you don't have one!). Also should test the diode is not shorted as well.
It could be the resistor just runs on the hot side and after all these years of running this 'old supply' it has slowly cooked itself and its surrounds.
The ceramic disk capacitor is most likely okay (cannot read its value but the volt rating is 1kV). Diode looks to be a standard 1n4007.
Maybe you should think of getting a DMM if you intend to tinker with electronic things, get a reasonable one and you will not regret it. (note there are PLENTY of threads on here asking about "which multimeter shouls I get".