I am repairing a 2004 Discovery 2 and found some rust in the footwell on the driver side (see attached photo). I have ground everything down and found that 90% will be easy to treat and seal. The issue is the other 10%. The area where the A column meets the floor and the sill (see attached photo). Is ther an easy fix or best way to approach thsi area? I haven't found anything out there. Any assiatance would be greatly appreciated. Cheers.