Maybe this is from the original production? Unless it's a theatre class, I doubt it would matter if it was actually the show as long as you've got Ethel Merman in it. I never found Ethel Merman to be particularly attractive, but I've never seen pictures so young of her. All I know is that this was 1930s-ish (which should be enough for the project) as long as you don't get pictures from the film in which she is older and with Frank Sinatra.
Or you can just put pictures like this of Ethel Merman young and explain that there aren't any reliable pictures of the original production if no one can find them.
