Levin Mandolin 8 string model 46 Classic. 1949.

Specifications: 8-string Mandolin. Flat back. Body width: 225 mm. Spruce top with undetermined bracing. Birch back & sides. Single-bound top. Single-bound back. Unbound headstock. Unbound walnut fingerboard with pearloid dot inlay. Nickel plated tuners. Sunburst finish. One year warranty. Introduced: ca 1947 ca 1949: Tuners with white plastic buttons. Latest known example: 1952.
Model info here: