Based on what I've read and just the look of the piece I would guess that it was made in the late 40's early 50's but again, that is just a guess. There is another band that looks very similar to yours posted on another website that claims theirs to be from the 30's. His career lasted some 40 years though so again, it's hard to say.
Wish I could give you a more definitive answer but I am no expert on the subject. (admin edit - see Posting Requirements )