Bruce Greenberg is coming out with a new Prewar Guide for Lionel. It will likely be around the April, 2014 York Timeframe. I always look forward to these as Bruce Greenberg really pays attention to detail and does his homework. While there will always be debates about production runs, staffing and color schemes, there really is no debate of how valuable these guides are. There really has never been anything like them before or since. Here is a link to a current page for Bruce:
I highly recommend you take a look at the web page and then grab a copy of the new guide at York or just before. It really helps make good buying decisions and intelligent planning for layouts and your roster.