Annie, I have rethought my comment... Since I'm sure you have saved the debrey from the ransacking of your sewing room....I think I would invite them over! Yes, everyone thinks that I'm crazy...but hear me out.
Sit them with the parents on the sofa. Make sure that your boyfriend is standing next to you or behind you, not sitting in a chair and watching the tv.
Show them the handiwork that they made. List all the things that are still missing and ask if they can tell you where they put the item. Then present them with a cost list of replacement items, including your time in fixing the mess, and the quilt ( which would have been priceless).
If they can't pay up, than sign a contract with each parent, and with each child for a work program. Lawn work, heavy spring cleaning, take them to a community work program,etc. If they won't do this, tell them that this could end up in a courtroom. Scare the $%#@ out of the kids. This will teach them that it isn't worth being a brat.
Oh, and by the way. If you do this, make sure that you have a really nice smelling dinner in the oven. And when the conversation is over, tell them to go home, it is time for you to eat YOUR dinner. Susie