Re: Valuation Reports...
Attached is a digital copy of Records Relating to North American Railroads, Compiled by David Pfeiffer, Reference Information Paper 91
And this link guides you through the attached document. https://www.rlhs.org/Services/Guides/
The first time I met David he told me what the Archives has was what the ICC gave them. He explained that there were records missing, because the ICC did not have them. It could have been a file left on someone’s desk, or a box that had been “borrowed”. The ICC records were often what they received from the railroads themselves. So in short the records were not complete, and that I may or may not find what I was looking for.
In addition many railroad prepared work in advance of the valuation. The M&StL, for example, had sketches of certain depots prepared and submitted to the ICC, because the original drawings disappeared. The CNW Historical Society has reproduced these depot sketches in a spiral bound book https://cnwhs.org/wp1/product/mstl-depot-sketches/ So be sure to check with the railroad Historical Society to see what they have published.