it's a secretary from duck soup!
and i actually have a pattern which is similar... actually, it's an evadress pattern for a pair of dresses, and i think the sleeves of one plus the bow of the other might be it.
lots of other gorgeous dresses in duck soup:
but realistically i am more likely to dress like the secretary than the dancer/spy (check out those bias sequins)! or, the ever wonderful margaret dumont.