This 1935 Diamond Jubilee commemorative medallion of the Pony Express was issued by the Oregon Trail Memorial Association and was struck by Whitehead & Hoag Had it so long in the sleeve it peeled nc climate casualty i think
Your coin looks like it has PVC damage. These are nice historic pieces. https://en.numista.com/catalogue/pieces87341.html https://en.numista.com/catalogue/pieces136252.html
I grew up right in the pony express trail. When I was in Boy Scouts we earned a medal by doing some stuff and riding horses 40 miles along the actual route.