Red Rita?
Was the girl who did the stage routine with the red head pigtail wig Rita?
As seen here:
https://www.imdb.com/title/tt0167165/mediaviewer/rm2145531648/
I think that was Rita (Martine Flety), but wasn't quite sure and it could have been some other girl. I can't remember if they ever showed that character come off stage and remove her wig to make clear that it was Rita or not. I see the picture tagged to her, but wondered if you thought that was the same girl.
Most of the cast in this one aren't people I recognized on site, and there are a few actress names credited (Betty Laure, Nene Kao) with no pictures and no other credits, so who knows who they were.