Larry,
I am currently building this kit, and I was stationed on the ship for 2.5 years starting in '95. I have some insight to the challenges/shortcomings with this kit. It is a good starting point, though, and is a nice and challenging kit for building together with your grandson.
When is your tour? One of the shortcomings with Nimitz ships is detail photos - take many if you have the chance, especially of the obscure areas (fantail, weapons platforms, etc). Of course, feel free to share any photos you take! ;-)
Let me know of your specific questions. You can reach me here or at lentzf@aol.com. And best of luck!
Fred Lentz