Your quilt is lovely and I agree more quilting will make you happier. It has been my experience that when you have an older singer or other types also you do not need a walking foot because the feed dogs are strong enough to pull your quilt through without having to have the top feed also. Make up a sample piece and give it a try but I think you will find it will quilt nicely without a walking foot and especiall if you take your foot off and use it bare needle you'll be able to do a great deal of patterns without turning your quilt all over the place. Be sure you keep your fingers out of the way.