As those are wax dipped, the simplest fix for them is a drop of candle wax on the capacitor, and a quick blast of hot air to melt it into the capacitor body again. Will reset the aging of the capacitor, but as it is a disc ceramic and will drift anyway, and as it has a -20% +80% tolerance, and will drift in this range anyway, resetting the aging with heat will not have any real consequence on use.
You might want to resolder the diode though, as it is going to cause problems with offset voltages, as the diodes are there to decouple hum, and the capacitor is there to reduce high frequency noise, so in use anyway will only have 0.6V across it maximum.