I have seen these for sale in the bobbin brackets on Ebay, about $12 for the whole thing. Do you still have the spring in place, that the felt fits into? If so, you can make your own replacement felt piece. My 66 has lost it's felt. People who don't know what they are for tend to throw them out, thinking they are some sort of fabric lint that got stuck in there... You know, you don't need the felt wick, really. Mine is missing the conical spring too, but as long as you put a drop of oil into the bobbin assembly every so often, you're okay. I have been piecing on my 66 a LOT lately, and I just put a drop of oil in there about every 4-5 bobbin changes.