Armour reefer underframe
Here's something I came across in the 1908 Railroad Gazette (online at archive.org)
It is the steel reinforcement used by Armour Car Line to strengthen their wood reefers ca.1907.
(note "Armour RSU 2" and "Armour RSU dwg" was added to the file names by me.)
I'm always looking for stuff like this-maybe you are too!