[LovesRolexes123]

dj7u, I doubt that anyone has the specific answer to your question readily available. You should call one of the Rolex Service Centers, and they will check with a technician and/or otherwise give you the answer to your question re: Serial Numbers / Solid Center links. Let us know what you find out.

Also, from my brief research, it appears that the all gold submariner existed WAY before the R serial number, perhaps with a model number of 16808? (I may be wrong on the number) (And other possible model numbers). So, it appears that the gold sub existed in a model number prior to the 16618, and there are books and a lot of info out there on these models I believe (but I don't have the energy to do the research any more on this topic!).