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Amazon.com: SIGMA 40” Acoustic Guitar, OOO, 4/4 Full-Size, with D'Addario EXP16 Strings, Solid Spruce Top, Vintage Tinted Gloss, Mahogany Back & Sides, Right(10A) : Musical Instruments
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MARTIN PROTOTYPE SIGMA ELECTRIC GUITAR CIRCA 1979-1980. THIS IS AN EXTREMELY RARE PROTOTYPE MADE - Able Auctions
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Sigma by Martin TB-1N Thin-Body OM/000 Acoustic / Electric w/ Cutaway, Natural - Previously Owned - Bill's Music
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MARTIN PROTOTYPE SIGMA ELECTRIC GUITAR CIRCA 1979-1980. THIS IS AN EXTREMELY RARE PROTOTYPE MADE - Able Auctions
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1981 Martin Sigma SE-28 Acoustic Flattop w/ Cutaway Natural > Guitars Flattop Electric & Acoustic | Rivington Guitars
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