Early Weissenborn Koa Wood Slide Guitar in remarkable excellent condition, no cracks with hard case. This rare guitar was built between 1921 to 1923. . A little history of the company.October 2, 1915, the then 52-year-old Hermann Weissenborn married the 25-year-old Concepcion. About this time, he began placing into his guitars a picture label of himself holding a steel guitar. Also, about 1915, Hermann met one Albert A. Kolb in a nearby lumber yard, who was able to provide Hermann with koa wood, beginning a long-term relationship. In 1921, Hermann’s then 31-year-old son Hermann Friederich August Weissenborn immigrated from Germany to work with his father Between 1921 and 1923, Weissenborn built a small number of steel guitars for Christophe’s Dept. Store in San Francisco under the “Italian Madonna” and “Maui” labels.