I am restoring a 72' Columbia 3-speed girls Stingray style lime green bike for my Grandaughter. This is my first project.The biggest obsticle seems to be locating the Sturmy Archer shift chain and mounts. Also we need a chain guard. Does any one know what this bike was called? I know the Shwinns were Stingrays.I see no serial #s on the frame. Any help would be great, thanks. Don.