I recently purchased a sigma that i have been unable to find any info at all on it is a thin electric acoustic cutaway with white binding made in Korea it is a cfm-2rtt the back is a bowed shape it says sigma guitars est 1970 in pearl inlay with a design on the headstock that runs down between the tuners also in pearl inlay,,, the sound is incredible,,, has anyone heard of this model or have any info at all on it thank you for any info that you may be able to provide