Because I was not able to examine all pages of the pamphlet, a copyright search of pamphlets and books was done for the years 1967 and 1968 for Chicago, Burlington and Quincy. There were no results.
Though I believe the pamphlet was never copyrighted, I have chosen to license it as not renewed to be certain.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
{{Information |Description=Photo of the dining car of the Denver Zephyr in 1940. The 2 diners were named Silver Service and Silver Grill. |Source=[http://www.ebay.com/itm/1940-CB-Q-Railroad-Burlington-Route-Chicago-Denver-ZEPHYRS-Distinctive-Trains-/4...