I have a 9 patch quilt that my Grandma made for me many years ago. She set the blocks together with red sashing and tied it. I have washed it in cold water a couple of times and it has held up just fine! I would wash the wool in cold water first, just to get the shrinkage down to a minimum, and use all wool throughout the quilt (blocks, sashing, borders, backing, batting and binding!) It would be a treasure!! Good luck and let us know what you do!