Here's a little something I found- some interesting history of the site, and of the old Astor Hotel. The writer makes some strange claims about goings-on in the present building, as well as an error about the building's first major tenant- he thinks they built it, for their own use, which is not true. They just leased a chunk of space and paid for the naming rights. But aside from a few quibbles, it's an interesting history:
http://mtv-1515-broadway.glennribble.com/?p=1