Everything unique on a coin isn't an error. It's estimated 99.99% of the time it's post-mint damage. And the reality is probably even higher than that.
I do believe Fred hit it on the head. Being a 1936 coin in that condition, it wouldn't be worth much, so maybe try using a small torch to melt it just as an experiment?
Was harshly cleaned. Which supports the jewelry theory. 1936 Philly is a common date. Without the cleaning and solder 25 cents. With the cleaning and solder 5 cents. This coin can be released into the wild.
I've never seen a Buffalo and I've seen a lot of them, with legs that strong. More like a jewelry piece or a button in the past.