[Eliot Ness]

Great news! Repairman found and replaced bad caps resulting in greatly improved fidelity

Mike just said it and many others have also, but it bears repeating.  You need to replace all of the wax/paper and electrolytic capacitors while the set is being repaired or they will fail at some point when you have the set all back together and listening to it.

Not all the caps are being replaced as many low power units have kept their tolerances.

 
Modern meters check the actual value of the capacitor but not at its rated voltage where it is most likely to fail or have excessive leakage.  Just for kicks I usually test all the paper caps that I replace and while some still read within tolerance, virtually all of them fail the leakage test at their rated voltages.  The only way to fully test those old capacitors is with an older cap tester that will apply true working voltage.

Rick, we don't replace those old caps because we enjoy doing it, but because we know if they aren't causing problems now they will in the near future.  We want you to enjoy listening to your tombstone radio without having to pull the chassis out again because of bad capacitors.