I bought my c.1961 Submariner from a jeweler who specializes in fine watches. He had just overhauled it when I bought it, but when I took it to Rolex B.H. (mostly for authentication) they reported that “Movement oils dry/gaskets worn”. Since it had just been lubed, I’m guessing that they found worn gaskets. (They no doubt enter a code that matches one or more conditions that they found.) If you take your watch to a a Rolex Service Centre you’re guaranteed that it will be up to Rolex standards. If you take it to a jeweler it might not be. (BTW: The watch runs fine. I’d just like to get a new dial with Luminova – I finally remembered the word – and they won’t do that unless you get the Factory Movement Service.)
Keep the case sealed? If the tech is qualified, there shouldn’t be a problem. There really isn’t a “seal” after all. It’s just a screwed on back. With the proper tool the back can be removed by anyone. As long as you don’t damage the gasket (I think there’s one, but it might just be a really good fit – I’ll have to check my book) you should be okay. But you’d have to make sure the tech is really qualified before you let him start taking pieces out.
Rolex have a procedure that they follow when they service a watch:
Diagnosis. Identification allows a paper-trail to be created or added to for your watch. Then they evaluate the condition of the watch and make service recommendations. (This is what happened with the two Subs – basically, and “estimate”.) The watch is then timed in several positions to check performance.
Disassembly The movement is completely disassembled and every part is inspected and ultrasonically cleaned in solutions to remove dried and congealed lubricants.
Lubrication The movement is lubricated with the proper oils.
Timing The timing is calibrated and observed and tested over several days.
Case and Bracelet The bracelet is examined and serviced as necessary. The case is hand-refinished. The case and bracelet are ultrasonically cleaned
Pressure Testing “Utilizing a vacuum and compressed air test, a Rolex technician will verify the unique protective features of the Oyster case in a pressure tank where it is completely submerged in water.”
Wrist Motion Simulation The technician puts on the watch and then heads off to the Men’s room with some porn magazines. No, actually the watch is put onto a machine that simulates wrist motion to make sure the self-winding mechanism is performing to original standards.
Quality Control The watch is examined one more time before it is returned.
There is no guarantee that an independent jeweler will do all of these things.
As for Vancouver, I’m not moving to Canada. They have this “thing” about people owning firearms up there. But Birch Bay, WA is only several miles from the Canadian border, and it’s much closer to drive to Vancouver than it is to drive to Seattle – about 1/3 the distance.