HI I have just became the owner of a Sigma CRS-6 serial 73032938 adjustable bridge, rosewood fingerboard, mahogany back and sides.

Very nice sounding guitar. I believe it was made in the early 70s at the Sada Yairi factory in Nagoya Japan.
I also have a Trameleuc AH10 serial 70270. I have an idea these guitars were actually made in the same factory both under license. The Trameleuc is one of the best sounding jumbos I have herd.

I would like to here from anyone who as interest in these instruments