Where to get custom display casebacks?

I have a Heuer Carrera Re-Edition CS3113 and I’ve been trying to find out where to get a sapphire Caseback because I really love seeing the movement especially being manual wind without a giant rotor in the way. I know it runs the Rick of water resistance failing but Ive been very careful whenever I wear this watch so I’m willing to take that chance. I’ve searched all over ebay with no luck and customwatchconcepts only does them for Rolex/Omega etc. Are there other people that can even custom make one? Any help is appreciated!