- acoustic guitars
Marwin was a Tonk Bros brand name. Tonk Brothers were primarily a mail order distributer. Marwin mandolins and acoustic guitars were made from 1930s to 1950s by Harmony (& possibly others?).
Source: Marwin & Tonk Brothers catalogs 1930s to 1950s
Tonk Brothers, Brunswick Building
623 South Wabash AvenueChicago , IL