[RodB]

If you look closely at the paper wax capacitors they probably have something like "outside foil" near the black band. This designates the lead connected to the metal foil that ends up being on the outside when the capacitor is rolled up. When that lead is connected to the lowest impedance side of the circuit it acts as a shield to external interference. Modern capacitors are not marked as such so you would have to determine electronically which lead is the outside foil. This is the only "polarization" of paper caps and doesn't have a considerable affect on the operation of the radio.

Paper capacitors are usually replaced with film capacitors. Other types may be used but they are generally much more expensive and won't make a big difference in performance. But I have some bumble-bee caps you can have for ten bucks each, a real bargain!