First off, nice radio & you did not go wrong at $5. The tubes alone are worth that!
You can get capacitors from
www.justradios.com,
www.tubesandmore.com, or
www.radiodaze.com. You should also get a schematic for your radio. Try
www.nostalgiaair.org. When changing those electrolytics, observe polarity. If these are wired in backwards, they may explode. You don't have to worry about polarity with the paper capacitors.
You should also invest in a can of Deoxit and clean all the controls and the tube sockets.