Doug, I don't want to be the bearer of bad news, but being able to register a Nikon product on the Nikon USA website DOES NOT guarantee it is a Nikon USA authorized product. I purchased a used Nikon D3 in 2009 from a private seller and he never stated it was grey market. Being proactive, I registered the D3 while it was in transit to me thinking everything was fine. Unfortunately when the camera arrived, it had neither the "(U)" indicator on the box or the "Nikon USA" sticker in the battery chamber. I contacted the seller about this and he admitted he purchased the D3 out of country. I returned the D3 and got a full refund. The box had a "(J)" indicator on the box.
From my experience, Nikon USA camera bodies have either the (U) stamp on the box next to the serial number, a "Nikon USA" sticker in the battery chamber or both.
Hope this helps...JL
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