I have several quilts made by my grandmothers back in the early 1900s. Some of them have what I call "age spots." I don't think they are actually stains. They aren't what you'd call gorgeous quilts, but were pieced out of whatever fabric they were able to get their hands on, most of it scraps from clothing they had sewn I think, and I really treasure them. I am wondering if there is anyway to make them look better. They appear fragile and I don't want to cause any additional damage.