I do not think so. The picture shows the stock resting on leaves and twigs which it would definitely not have been if there a long time.
The article said the stock was buried partly into the ground.
“The 132 year-old rifle, exposed to sun, wind, snow, and rain was found
leaning against a tree in the park.
What do you mean, "I don't Think So"? I didn't pull that out of my ass.
The Pic in #16 is exactly how they found the weapon!
Good Freaking Grief.