Global Flat-Backed Mandolin Market Size, Share, Demand Analysis Report By Product Type (Handcrafted Mandolins, Factory-Produced Mandolins), By Distribution Channel (Online Retail, Offline Retail (Music Stores), Direct Sales by Luthier), By End User (Amateur Musicians & Hobbyists, Music Students, Professional Performers, Collectors & Enthusiasts), By Region & Segment Forecasts, 2025–2030.