I had a client that many years ago had made a quilt top for me and she had marked it with a Blue be gone marker and then PRESSED the quilt. I explained to her the mistake she made and then soaked it overnight in a product I love for washing linens called Linen Wash by Le Blanc in FL. I was amazed that the Blue be gone was absolutely gone. Since yours has been marked for a number of years, I am not sure if the product will work. Have you thought about applique something like a doily that will cover the markings if they don't come out?? Good Luck.