Go to just radios, Mouser, Allied, Digikey, Capacitor World, etc and look at the electrolytic caps available.
They do not make caps in that exact form factor anymore (and NOS ones are crap) so you will have to use smaller modern caps to replace that can. Read the value(s) on the original can.
Odds are the can contains more than one cap. The values should be something like ##uF (or ##MFD if older notation) ###V along with a symbol (D,,V,'-' or blank) indicating which of the inner terminals the positive lead connects to. The positive terminal will have the same symbol as the corresponding value on the label does. The negative terminals are all connected to the outer metal can (there are exceptions but those are rare).
When ordering replacements you will want to order one for each section of the original can. You will want to order the same voltage value or higher (NEVER go lower voltage), and you will want the same or close capacitance within 20-50% tolerance.