Edward Budd Company, Philadelphia. The company's name was applied with a seal to the lower right corner. It's not very visible but we have another Budd built Flying Yankee train photo with the mark for comparison.
Since I couldn't view the backs of the photos to look for copyright marks, a search was done for renewals in the artwork category, where photos are listed, for the years 1962 and 1963. There were no listings for the Edward Budd Company, Budd Company or any variations. There were also no listings for the Chicago, Burlington and Quincy Railroad or any variations (Burlington) of it. The Burlington was the owner of the train built by Budd.
While I believe the photos were never copyrighted, I have chosen to license this as copyright not renewed to be certain of a correct license.
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=Budd Company photo of the Pioneer Zephyr. This is number 9900, which is the Pioneer Zephyr. |Source=[http://www.ebay.com/itm/27pc-LOT-OF-RARE-ORIGINAL-BUDD-COMPANY-ARCHIVE-BURLINGTON-ROUTE-ZEPHYR-PHOTOS-/321173524859?pt=LH_De...