This project is currently in progress for the masquerade at Sakuracon, 2015. I decided to move forward with a Butterick patter - #4731. This pattern has the exact shape of the gown that I needed, complete with small train.

As of 6/22: The outside of the dress is complete, and the lining is sewn. I'm now working on creating the bodice (which requires boning, a foundation, lining, and interafacing) and sewing everything together. This dress has been a little more challenging than I would have liked to begin with, but I think that with a little assistance, I'll be able to finish it up soon.