http://cdm15020.contentdm.oclc.org/cdm/landingpage/collection/p15020coll4
This one is particularly interesting:
http://cdm15020.contentdm.oclc.org/cdm/singleitem/collection/p15020coll4/id/922/rec/60
I've been searching for an OK 33 shield on Skelly Drive and I finally found one. This picture was taken between when US 66 was decommissioned and US 412 was extended.
Here's a pic of a US 66 shield:
http://cdm15020.contentdm.oclc.org/cdm/singleitem/collection/p15020coll4/id/1529/rec/58
Button copy I-44/US 66/OK 33:
http://cdm15020.contentdm.oclc.org/cdm/singleitem/collection/p15020coll4/id/904/rec/74
http://cdm15020.contentdm.oclc.org/cdm/singleitem/collection/p15020coll4/id/1333/rec/64
http://cdm15020.contentdm.oclc.org/cdm/singleitem/collection/p15020coll4/id/877/rec/84
The railroad signal in the last one there looks a lot like a Wisconsin stoplight arm.