Tiffany & Co. Identification

[sypher.mp3]

I was wondering if anyone could help me identify and have information on this Tiffany watch. I inherited it from my great uncle, who apparently bought it in NYC during the late 70's or early 80's after graduating from grad school. From what I was told, it was quite expensive. I dont have any documentations, nor have I opened the case up to check out the movement. It's worn well, but I really do enjoy wearing it because of its simplicity and small size. Anyway, anyone seen something like this?

[baronrojo]

Without opening the case there is no way to tell what the watch really is.