I doubt there's much use for this guy's  products, but I thought his good service deserved a mention. My wife's Cartier Tank Francaise Rep lost the little blue stone from the winding crown. I tried to get a replacement crown, but no joy (its a few years old, not a popular make) so I thought I'd try and get a replacement stone. After a Google search I ended up on Etsy and ordered a 2mm cabochon from seller Selectedgemstone. In the order comments, I asked if it could be flat backed as it was for a Cartier winding crown. I woke up today to four emails from the owner saying he can make the perfect stone, asking for photos of the Crown so he can see what depth of stone is needed, telling me what shape works best in the crown etc - mega helpful. This is for a purchase that cost a few quid. Awesome service and seemingly backed up by 5 star reviews across the board on Etsy. If you need a gemstone, whether very cheap or extremely precious, this guy seems excellent.