Vintage 1928 National Tricone Style 3 Square Neck Resonator GuitarNotes Serial Number: 506 (stamped on the back of the neck, indicating early, low number production). Offered here is an exceptional, early production masterpiece from the dawn of the resonator era: a 1928 National Tricone Style 3 Square Neck, featuring the highly desirable and intricate "Lily of the Valley" engraving. Bearing serial number 506, this instrument represents a very early, pre production refinement example from the famed Los Angeles