I have been working on removing a passenger trunk drop for my car..I have a 71 inner and wheelhouse that I kept for that exact reason.The wheelhouses are salvageable but they would need brackets trimmed off and outer has a quarter sized hole that would need fixed. Not sure I want to trim it up the rest of the way or maybe selling it off. I have all new wheelhouse for my car already.
Best thing I ever found was an air chisel. Then, after destroying my rocker panel and having to re-weld the air chiseled hole, I have now chosen to switch to a seam splitter. Little more controllable.