Here's a link to a website that provides information as to Nikon serial number country of origin, as well as a lot of other information concerning each Nikon model: http://www.photosynthesis.co.nz/nikon/camera.html
I have a 17K Generac automatic stand-by generator that continues to serve without a hiccup.. I have the oil changed annually, and the battery every three years..
I suppose that this may be old news, but here is a link to a website that lists the region to which Nikon camera and lens serial numbers are assigned.. If this information is accurate, it would seem to be a quick way to distinguish between Nikon US and gray market products.. http://www.photosynthesis.co.nz/nikon/camera.html