I thought about making Moxxi too, but I haven't gotten past the research stage yet. Here's what I found so far in terms of patterns for that jacket. Adding a collar could get tricky, but I think the TV's dinner bodice is your best bet.
http://www.trulyvictorian.net/tvxcar...5&cat=5&page=1
http://www.trulyvictorian.net/tvxcar...3&cat=5&page=1
http://www.trulyvictorian.net/tvxcar...p?productid=51 (I thought this seemed closest and easiest to modify).
This could also work:
http://store.reconstructinghistory.c...70s-1910s.html
Good Luck!!