I am attempting to re-cover the cushions on my lawn furniture. The top cushions all have buttons in the centers. They are plastic and look like 2 of them have been snapped together, one from one side and another from the other side. If you hold onto one side the other one will spin, but I can't get them apart. I can't find anything like them on the internet so I am looking at " Dritz Home 1.13 Nylon Upholstery Cover Buttons Round " at JOAnn's that seem to be the correct size. Will these work....are they buttons that you can cover? If I sew 2 buttons together in the center with heavy thread, won't that work?