heavily stained coin, maybe in motor oil or dirt for a long while, What's this circled in red though? that's odd unless you have something behind this coin?
You mean Broadstruck ? Off center would mean it was missing letters or anything for that matter along the edge .
Your quarter is just Environmental Exposure Damage. Starting in 1965 quarter planchets were Cupro-Nickel clad on both sides with a copper core. The copper tones depending on the environment is was in for an extended period of time. Yout quarter in not any kind of Mint Error. Here are examples from my metal detected finds