Lindy Bop 1950s Style Navy Blue Swing Dress

This is a Lindy Bop (RIP) Navy Blue with Black Bodice Swing Dress. I wore it once to a wedding, but it never fit properly. There is a whitish stain on the front of the dress less than an inch in width. I tried a stain remover on it, but to no avail. So I'm just marking down for less and hoping someone out there will know how to repair the dress and want to buy it!