I have some AAR manuals for sale.
I have the AAR's "Rules Governing the Loading of Commodities on Open Top Cars" for 1942 and 1945. $55 each These are the full document, 420+ pages, not the smaller specific loading pamplets.
I also have AAR Interchange rule books for 1953, 1958 and 1985. and Maintenance of Brakes and Train Air Signal Equipment 1942. Prices in order of mention $15, $15. $10 and $7.50
If interested, please contact me off-list.