First of all, I wouldn't mess with the bezel which is the metal part. You're not going to be able to find a part that fits probably.
Now for the insert, if you have an SSD, Super Sea-Dweller, your best bet is to do the BK mod- buy a watchmaterial pearl from www.watchmaterial.com. Then remove the insert- the black part, pop out the pearl, enlarge the hole slightly and install the new WM pearl w/ a dab of glue. While you're at it, file down the back of the insert and then reinstall it w/ a little bit of glue. At that point it should sit slighty lower in the bezel and look a little better.
Good luck.