Again, I wish I had seen this earlier!
Go to the guild website, and find Laurie's contact information. She specializes in altering bellydance costumes - you should have seen what she did for last year's Jawaahir show! I'm not 100% sure about rush jobs, but it never hurts to ask.
She is a great dancer and teacher, too.
EDIT:
Here is the link
Guild of Oriental Dance: Middle Eastern Culture
I am recommending Laurie because I know someone who has had her work on vintage bedlah before. She said it was great work, but she paid for it.
I also know Louise and Kristin from that list. They always look great in fabulous, appropriate, and well-fitting costumes, and I would trust them to do any work they felt capable of doing. I assume they fix bedlah, too. I've been wearing one of Kristin's chemises out at fest for the past 2 years, and it fits and wears beautifully - I know Kristin's been doing costuming for a long time. Louise ran a sewing seminar for the guild, and she really knows her stuff, too.