One of my favorite TCO books is the classic The Tiffany Touch. The PR presentation I used to do when I worked for Tiffany's was a lecture/slide show based on this book, and it fascinated people to learn all about the Tiffany story. Many thought that Louis Comfort Tiffany's glassworks had once been part of the store (not!) and all were surprised to read about the merchandise that TCO sold in its early days!
The book came out in hardback and then paperback and I am so happy to see that it is widely available through Amazon.com and other used book sellers.....for a good price, too!
I highly recommend it......It is the definitive "story" of the birth and growth of TCO. It will give you great ideas for a New York City treasure hunt, too. TCO did not start out at 57th and 5th. Get the book and find out where it did start.....then head on downtown!