Visited by the ghost of the 1940?s Hollywood icon she?s about to portray, a movie star journeys back in time to get her part right and get her Oscar.

Sounds like the lead character found a solution to her problem. The lead wants to win an Oscar and so she travels back in time to observe the real icon in action... problem solved

So where is the conflict?

What stands in the leads way?

I only ask this because adding the main conflict of the story will strengthen your logline.