I recently bought a 20 to 30's quilt and bought some stuff from quiltinaday web site to get the stains out of it. I can rembember the name but you let it soak in the mixture in the sun. I talked to someone who does alot of this stuff and she suggested mending in reproduction fabric to match what was already done. If possible I'd take the square out that had the hole in it and replace it. I'm sure if you looked around and found some quilting museums and asked them might say something else so it's up to you. The one thing that I was told was try and not fold it the traditional way and then ever so often go back in and refold it so that it doesn't get those fold stain lines in it.