I was wondering if someone could help me figure out when my Sigma 12 string was made. It is a DR 12-7 serial number is Z2914. It also says manufactured in Japan.

I've read through most of these posts and never seen anyone else mention the letter Z in a serial number. I bought it used in the early 80's and I don't think it has a solid top or back and sides.

It's been sitting in my closet for 20 years, and I was thinking about selling it, but I was hoping to find out a little more about it before I do

Thanks, Keith