First, welcome to the forum. I'm not an expert at playfield repair but it appears that you'll be needing to raise the level of the light inserts to the playfield. It looks like they've shrunk/sunken below the level that caused the ball to make the wear marks on the back side.
There are a couple of things you can do.
- If your aren't good with color matching or painting for the matter, you might look for a good scan of the playfield and make some patches for those worn spots. There are some excellent websites that show you how to do this.
- or you can repaint those worn areas. This is much more difficult and will need very good color matching.
If you can't match the paint well, it is better to just leave it alone and address the light insert level issue to prevent more wear.
Rubbers are rubbers. Look for the best price w/ shipping. You can save a little money if you know the sizes you need and can order individually. Good Luck.
Regards,
Russell