Having the sapphire crystal replaced by a 3rd party shop (K2) whose main proprietary servicing brand is Seiko, if I were you I’d rather go back to RSC, understandably it’s more costly but I know it’s being serviced with a sense of security in my heart.
At least the crystal being replaced still has the Rolex crown etched at the 6 o’clock position. With a S inside the small circle coronet, to depict ‘Serviced’. Not to mention the waterproofing gasket too. You’d trust K2 will do a good job waterproofing for you?
Refer to this article:
First and foremost, if you have a chipped crystal and go to RSC, guess what. RSC will not change the crystal for you only. They will insist the entire movement be serviced, as they want to ensure none of the chips went into the movement. Don't ever think that RSC will let you go so easily without earning your money. No matter how much you argue or bang table, the answer will be no, they cannot simply change the crystal and gasket for you.
Waterproofing gasket around the crystal for Rolex is no big deal, super basic to do. Even those pre-owned watch dealers at Bencoolen or Golden Landmark can do. They have the original Rolex rubber gaskets too, which isn't expensive.
Dunno why many people kiasi until like that. It's a Rolex, a mass produced brand of watches, numbering well over a million units a year. It's not some ultra rare haute horological work of art.
Once you play Rolex, you know that original parts and accessories are readily available, even though Rolex S.A. doesn't supply independent watchmakers anymore. You just need to know where to look.
One very obvious place to look is Chrono24, if money is no object. It will still be cheaper than going to RSC. You can buy the original crystal which comes with gasket from the European dealers there. Sealed in the original Rolex packaging.
Then bring to your favourite watchmaker to do. K2 is more than proficient in doing this simple job. It simply involves wedging the bezel off, taking the crystal and gasket off, blow blow the dial to remove any dust, putting the new crystal and gasket on, putting the bezel on, and press everything together with the bezel press tool.
If you have the know how, you can do also. It is not rocket science.