Thank you all for your excellent suggestions. I have just received my copy of "Nikon a Celebration" by Brian Long: great reproductions of ads and a lot of useful information. I also ordered "The Nikon Camera in America, 1946-1953" by Michael Wescott Loder. From what I've been able to see so far just leafing through the book, it seems a very interesting read.
"The Nikon Manual" by George Wright is next on my list, thanks Joerg for the links to amazon.com and abebooks.com, I will place an order soon.
Guess I won't be short of reading material for the next couple of weeks... 😀