Personally, I wouldn't do it. Just reading your description of what's wrong with the quilt is making me cringe. So many, many, MANY frustrating, long hours of work. If it is truly in such bad shape, and the owner has a very small budget, you will never get paid what you should. You will end up feeling resentful and regret it. Some things are just beyond repair.
If the quilt has sentimental value, it might be better to not repair it, but instead frame a portion of it.
Last edited by Peckish; 01-18-2018 at 10:57 PM.