I noticed that they had an eBay store as well...Good Old Gold carries their setting line. They have a website with some really lovely vintage style settings. But, the prices seem very high. The also sell a lot of rings with the diamond already mounted, but I noticed they had better clarity stones listed on the eBay site versus their website.
I would review their feedback and I would also call GOG and see if they had an opinion about their settings. If you do a search here, not much comes up. Sounds like the company had some issues a few years back. http://platinumplusdesigns.com/