"It's a start."

The dress fits correctly now. It's also had a bit of alteration, with some subtle padding added to fill out his figure a little more and give the illusion that the corset is more tightly-laced than it really is.

The wig, makeup, and shoes will be the easy part. He's dealt with all those before. Once he's put them on, and learnt what he needs to about the appropriate mannerisms from Irene, he'll be indistinguishable from any other woman on the street in her London.