Very nice watch you have there. Here is some info I picked up on the Rolex gold shell cases. Rolex service in Toronto, Canada informed me that the gold on these cases is 40mm thick and it is an actual layer of solid 14k fused onto the stainless steel.
I had a gold shell case that was worn in a spot and I wanted the gold removed so to use the case as a solid stainless steel Date case. A jeweler friend went to work to remove the gold and in the end had to sand blast it off. He tells me it was a far tougher job than he expected. In the end he removed all the gold but it took a lot of work. These gold shell cases from Rolex are far different than a simple gold plated case.