Good wool is hard to find

I picked this up at the second hand store for $14. No tags, and I haven't done a burn test to see if it's 100% wool, but gee golly is it toasty, and my alergic to wool friends itch when they touch it.
We have wool blankets from my grandmother's estate, the kind from the 50's with the satin blanket binding and pastel colors that just won't quite pass 1750's muster.
For resons as yet unknown to me, herringbone would have been used as a blanket, but not apparel. Maybe because a plain weave was easier to set up than a herringbone, thus making plain weave cheaper and herringbone dearer...? Again I don't know.