Not sure whats going on with this. I have an idea of what I think it is, but I'll let the experts comment first
Let me say this thread may help. https://www.cointalk.com/threads/environmental-damage-or-works-of-art.289634/
Your Quarter has been in circulation for 45 years. Wear and tear will cause the look it has. Not a Mint error.
The extra metal near the bottom error comes extra metal being pushed out of the gouge next to it. I am willing to bet that there might be scratches around the other "extra metal" areas. When an old coin has a lot of wear and environmental damage, any surface anomalies are nearly always due to PMD and not mint errors