MADOLIN, SIGMA. Other - Musical instruments - Auctionet
DISC Sigma SMA-6 All Solid F-Style Mandolin, Sunburst at Gear4music
Mandolin Cafe Forum
Mandolína SIGMA GUITARS MA-1 - Hudební nástroje Houdek
Sigma SM-1 Mandolin for Sale in Concord, NC - OfferUp
Sigma SM6S "F" Mandolin Sunburst circa 1980s | Reverb
My “at work” mandolin. Sigma SM 23. I have no excuse for not practicing. Now, can we skip ahead to the part where I am awesome, and can play every O'Carolan tune
Martin Mandolins for sale | eBay
Sigma Mandolin 1971 Japanese made Martin Copy : The Steel Guitar Forum
Martin Sigma SA-1 Mandolin 1980s All Solid Woods Original Hardshell Case | Reverb