From Merchant & Mills:
This is a PDF pattern that will give you the relevant pattern pieces to make the Factory Dress into a Top, with either a middle vent or a side vents, or both.
Our model is a size 10 and is wearing a 14 for an oversized slouchy look.
NOTE: Please note you have to already have the Factory Dress pattern in order to make this, these are just the additional pattern pieces with instructions for those parts.