That doesn't sound right. Matbe you should check that label again?? Maybe i haven't been paying close attention, but I don't think Blueridge has been around that long, and Sigma was a Martin owned brand made in Japan and "assembled " in the US. 'Course, I've been wrong before!
Steve,
You may be right, I'm just going by what the owner told me. The label in the guitar has been removed. I'll check further with mirror inside to see if I can find any info.