This costume is an example of heavily altering pre-existing clothing pieces to create an accurate costume.
I created the neck tie and brooch by hand. The brooch is a base of Sintra (PVC foam board) with 3D paint on top for the birdcage design. I then painted it with acrylics and sealed it with Modge Podge glossy.
The skirt and blouse were pieces I already owned. I altered the skirt by adding the white trim and red belt. I altered the blouse by replacing the existing cuffs and collar with black ones with white trim detailing. I also added buttons to the cuffs and extra hidden snaps to the bust area to make it lie more smoothly.
This is the reference image from Irrational Games:
