ok so after hours upon hours of work I have found a good method to restore the bumpers. here is a half-second comparison.
before
https://drive.google.com/file/d/1sDsRn6IvtLAojLZgf-aE8Vz0NMRcWLnd/view?usp=sharing
after
https://drive.google.com/file/d/1g0jF-75kdgO2NQ-G7jYIRPdG_0bRZ4n-/view?usp=sharing
does anyone have any thoughts?