you can buy a lower door repair panel. I repaired my doors using welded patches(from an old hood), then filled the corners w/brushable seam sealer to completely fill the lower corner that traps water, now they are smooth inside on the corners, water will drain out now. I did this to my 79 Ford about 7 yrs ago, still good, it is stored outside(the 2 Chevies are inside the shop),,brian
