S.C.
Maybe you already solved this problem already. I contacted the company online, and they shipped me rings to fit the wide nipples with my existing bottles. They told me they were available in some sort of supply kit in stores, but I've never seen them. Plus, I had everything but the nipples, so I didn't need any sort of kit. Hope this helps! It was very annoying to me that the package claimed they fit all standard Medela bottles.
P.S. As per other responses, the older Medela bottle are all BPA free, I checked.