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Parsing this data with the MSExcel Text Import Wizard is quite error prone, but it worked for a quick test. The file is longer than my outdated version of Excel can handle (>65535 rows). For the previously posed question about cut stone products, there is an Standard Commodity Code (STCC) series for it (328**), but in what I managed to open of the 2011 sample, there was only a single 32819 Clay Stone Products shipped in a trailer on a single unit flat car.
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The STB website only has the previous 11 years (starting with 2011) of data accessible. I've seen references to this data existing as far back as 1986, and for $80 USD, the 1988 to 1992 data is available on CD-ROM. I also found a good reference for AAR car types.