[Eliot Ness]

If you are referring to the shiny caps, they are not replaced; I just polished the tops...

No, Mike (morzh) is referring to the two electrolytic capacitors circled in red below:

   

They are obviously not the original capacitors so they were replaced at some time.

As far as your radio not receiving it could be as simple as a bad tube or some other component.  The most commonly replaced items in these old radios are capacitors, resistors, and tubes.

First make sure no wires came loose when you cleaned the chassis... take a slow long look with a strong light (emphasis on long and slow) looking for anything amiss.  Also, just for kicks put that old 24 tube back in and see what happens.  Sometimes it's hard to see the filaments glow and it is possible you swapped out a good tube with a dud.

Then report back with a picture of the bottom of the chassis if you don't mind.  As far as the volume being scratchy you might be able to clear that up with a squirt of WD-40 into the pot if you can find any openings.

One more thing, are thopse screw tops on the two capacitors I circled in red?  If so unscrew them and take a good picture for us...thanks!