[cmjones01]

I'd just like to point out that the scorch marks on the chassis near the smoothing capacitor are likely to be nothing to do with the capacitor. I can't think of any failure mechanism that would result in black scorch marks near an electrolytic but an intact capacitor. Yes, the rubber on the bottom of the capacitor looks perished, so it's worth checking it, but the blackness is something else. I'm pretty sure it's just years of dust accumulated from convected heat from the two resistors directly underneath that area. It doesn't indicate any kind of fault; just long use.

If the noise appeared and has now gone, I respectfully suggest that randomly replacing capacitors is only likely to cure it by accident, and has the chance of introducing new problems. Try to find the actual fault rather than replacing everything. If you do replace components, test the radio after changing each one and see what the effect is. If it makes no difference, perhaps the original component wasn't faulty.