mystery item randomly found in an attic

[void]

i tried googling a bunch of keyword combinations related to the item's appearance as well as an image search & the suggestions were an old dog license tag or a bridle rosette, neither of which seem correct. about 3/4" tall by 5/8" wide. any ideas? it's driving me batty not knowing. thanks!

 

[Full Metal Digger]

My first thought was it's a RR tag of some sort. I don't think it's related to luggage, but maybe a tag for a wooden crate or even a telegraph pole. A little searching on Google and I found this:
https://www.bing.com/copilotsearch?q=US+KN+railroad+tag&form=CSBRAND

Understanding the “US KN” Railroad Tag​

“US KN” is the reporting mark for the United States Steel Corporation’s Kansas & Nebraska Railway, a historic shortline that operated in the U.S. and whose tags are now collectible railroad memorabilia.