Driver fender is a hot mess...

That fender is savable.
Take it off and evaluate, it was most likely a straight fender off a parts car that the bottom was rusted, somebody brazed and non rotted fender bottom on it.
If you really want to remove the brass, you will have to heat it up.
With no torches propane MAP gas will get hot enough to remove it. But then what do you have, a fender that is not usable.
Take it off, hammer and dolly it straighter, and move on.
Or find a nicer fender.