The leading man was played by Randolph Scott, who I gather usually played in Westerns, but he was especially cute and charming in this movie - he had an open face that most of the romantic leads of the era didn't have, and a great "gee, you're swell!" gaze.
Even the OH had never heard of the movie before (it came in his Fred & Ginger collection). There are a lot of rave reviews on IMDB. We were speculating why it never became as popular as other Fred & Ginger movies. Maybe because Fred & Ginger aren't the official romantic lead stars, they're supporting actors (although they have plenty of screen time and they do have a romance). Or maybe because there's a death, or exiled Russian nobility, or a lengthy fashion show. Who knows?