I continued my research and discovered that B.C. Stromqvist was once the owner of a music and tobacco shop in Sweden! He wasn't a lutier himself, but sold a lot of lutes, mandolins and guitars! Apparently this guitar was made by Bjarton and sold at Stromqvists! It went out of business in 1990. I even found a couple of pictures and found out that in the 1920's Stromqvist moved his store to a place that included a studio and recorded for Columbia! So very neat
Last Edit: Apr 25, 2015 19:47:20 GMT -5 by jan: Found some new info!
Strandqvist had a music store and studio in Helsingborg, Sweden. He started his music business around 1900 and sold records for Columbia, for whom he also made recordings in and around Helsingborg, with Edward Persson,, Evert Taube and others. The music store was eventually sold by his son, and went out of business 1994. I have an old Levin guitar with a metallic plate with the name B.C. STRANDQVIST HÄLSINGBORG. The Levin label, however, is intact. B.C. stood for Bernhard Carlsson.