Pete is friend, and I have no doubts he will do an excellent job. However turnraound time for Nikon RF CLA's at CameraQuest averages 3 to 4 weeks after receipt -- not two months.
Nikons were not sold gray market in the US at that time, nor were any other German or Japanese cameras for that matter. The camera graymarket simply did not exist in the US at that point in time. Check the old US photo magazine ads -- you won't find ads for gray market cameras. For that reason S4's were long abnormally rare in the US, while easy to find and unwanted in Japan.
The estimate I made on my S4 page about 10% going to the PX was just a guess based upon my experience. The actual figure could easily vary 50% or more in either direction. We simply don't know the exact figures.
Stephen