I have had old quilt tops with stains. I usually just wash them on the hand wash cycle of my machine, using small amount of regular laundry detergent to see if that takes it out. After washing check to see if the stains are still in it. If they are do not put it in the dryer. Drying it would really set in the stain. While wet, if the stains are still in it I mix a small amount of comet with water to make a paste and put that on the stained area. Let it sit for about 15 min. and then run it thru the hand washing cycle again. If the stain isn't out then you can forget getting it out. That has been my experience anyway.
PS: I read this board all the time but have only posted a couple times. I love this board and all the expert advise that I get here. Thanks