The Centaur II is an older machine(might be 1970's or 80's). You may have a difficult time finding one. They have plastic gears and the bobbin winder was problematic. This website
http://www.ecrater.com/p/14639931/si...sewing-machine lists other models that use this bobbin. There is an Ebay listing
http://www.ebay.com/itm/6268-Singer-...item3a8785a939 that uses this type bobbin. Check out the pictures. You can see the bobbin in the bobbin race.