I love buying wool at the Salvation Army. I've felted some and made a wonderful wool lap quilt for my fil. He's in a wheelchair now and has to be pushed a few blocks to dialysis. The wool really keeps his legs warm. I found a great men's wool jacket the other day - interesting rust/amber color. Man bought it to wear though :) He did look good in it.
Good find, of course have it cleaned or wash in cold water and air dry. Throw in a white rag to see if it bleeds if you're worried about that.