Lord Elgin Thin Thin 30 B
I’m not really so sure about how Elgin named their 30 jewel autos. I now have two different watches that Elgin called Thin Thin 30 B. This particular example has a very nice dial, but the 10K rolled gold case has a few “issues.”
The watch uses Elgin’s 30 jewel, American made 760 automatic movement.