When I first found the "flap" a radiator shop cut in my inner fender many years ago when I had the motor replaced, I was unhappy. A couple years ago when I replaced the heater core and hoses, I was real happy it was there. When a fender has not been off for 35 years, it is not an encouraging prospect to be trying to remove it and then get it back on straight.
A bead of seam sealer and a shot of the factory style undercoating and it is difficult to see anyway.
