I have only had one twelve string in my life; got it in 1961 for $48.50 and it was a Stella. No, not the GOOD kind that Leadbelly had but something made mainly out of plywood. When it came from the factory it had unison G strings and with nobody to talk to or learn from it was about a year till I got Fred Gerlach's record and saw that the 3rd pair was also tuned in octaves. I also started with it tuned up to concert and quickly tuned it down a full tone, where I kept it until it imploded some years later. For the ten years i had it as a workable instrument, I called it a combination hygrometer and guitar; you could made a good guess of the realtive humidity by the degree of warp in the neck. Maybe it's almost time to buy another twelve. . . twilight is stealing!