and three-cone components of the Nationals. Dobro Manufacturing Company licensed designs and supplied trademarks and parts to a series of vendors such as Kay-Kraft, Harmony (Sears) and Regal. George D. Beauchamp retained control of the National String Instrument Corporation. The two companies clashed in court from 1931 until 1935, when the Dopyeras prevailed and the National-Dobro Corporation was formed. The company moved to Chicago in 1936-37.

Mandolins sold under the Dobro brand had wooden bodies. Mandolins sold under the National brand