I believe the "T" denotes Tenor. Must be early, since Lanikai uses a different naming system now. Mom had a concert koa wood that had a very open grain. It's just the nature of the wood and I would not assume that it was more or less better than a smoother, tighter grain. I think all Lanikai are made in China. That being said, in my experience Lanikai is a perfectly acceptable instrument. I would look at the condition, quality of workmanship, and how it sounds.