I bought a Korean made Sigma DM-12-4 at a pawn shop this week. You don't see many older 12 strings that are playable, but the action on this one is still good. The number inside next to the truss rod adjustment says 83007, and the serial number on the inside sticker says 8301729. I love to play a 12 string, but not many of them last long. You can't beat the warm tone of a seasoned older guitar. I have been fascinated by all of the information in these posts. Any additional info would be appreciated.