Is pure hokum, but it does feature Joan Bennett and as a brunette. The cast includes Doug Fairbanks ( jr ),Vincent Price,George Sanders and George Bancroft on a treasure hunting expedition to South America.
It's been a while for me but I seem to recall that I enjoyed this fun movie, largely because of its sterling cast. I think I can at least tolerate anything featuring (1) Vincent Price and (2) George Sanders. And while I suppose I'd rather James Whale had finished his career with another type of film (that would've been a grand monster movie), I don't consider it an embarrassment, either.
It's one of those "Saturday Afternoon at the Movies" features that Carol Burnett might've parodied on her show ; or the type of thing they might've remade as an ABC TV movie in the 1970s with, say, Erik Estrada, Jaclyn Smith, Donald Pleasance and Ray Milland.