I've joined the Sigma Owners Group.

An SDR-28 was for sale from the original owner, who bought it in about 1995 and never learned to play. It sounds very good, nice tones, lots of sustain, and bass is not too boomy. This one really sings when tapped, just like my hammer dulcimer.

Headstock has Sigma Guitars EST. 1970 (underlined) in MOP. Pearlish fret dots. Paper label inside says Sigma - Prepared and Inspected by C.F Martin - Made in Korea. Serial 90041052.

Solid spruce top, rosewood sides and back may be solid. Glue job is neat and interior construction looks fine. Fingerboard is a very dark wood with slight reddish and black tones. Chrome tuners with no markings. Finish looks good, not overly thick.

I'm happy with it.