The thing that makes any antique more valuable is called provenance. Which of course is when you have the documented history of ownership and the makers information. You have that and we all need to write things down to document what we know and what we do. I always think I will remember later (like old photo info on the back). The value of these wonder quilts is the sentimental value to you as well as the info you know. Repairing or not is not the real issue but documenting what you do to it. I try to remember that my life is short and fleeting and my daughter or son may want to know the provenance. As for where to find materials....I often have purchased for repairs at local antique shops. They ofter see a value in yardage or sacking fabrics. Good luck with your awesome gift of family and history.