Hey georbro, is your Sigma solid or laminate top? When I got mine I thought it was a solid top but after having it outside in sunlight one day I figured out that it is a laminate top. (Mild bummer for value but I still love the sound) I'm guessing mine may be from right around the transition time from Japan to Korea as it's stamped made in Japan but the number on the neck block has a K in front of it. Of course, that may be coincidence? I just bought some Martin acoustic SP 80/20 bronze strings for it today but have not put them on yet.