Control arm bushings question

The ones I removed were rubber, the new bushings are polyurethane. Again, it fit perfect, pressed right in. I did try to look up the old part's number, but it seems to be a product that is no longer available. Could be a part designed to replace the factory bushing without an outer shell, that was made prior to the popularity of poly bushings. I will have to post a picture of the old ones and the new parts installed.