The National Company are most famous for make steel, resonator instruments. These instruments produce plenty of volume. Even the tiny ukulele creates a huge sound.
The company began producing instruments in the 1920s and their design shows it. Some of the best instruments are designed in a heavily art deco style. Many National ukuleles will be engraved - sometimes highly elaborately.
The 1920s reso-phonic ukuleles are one of the ukes I intend to add to my collection once I win the lottery (admittedly, that's a very long list)
Bob Brozman has a huge collection of vintage resonator instruments including this ukulele. Even on video, you can get an idea of the volume it's capable of producing.