It happens to be doors which swing rather than slide. We've fixed the damage underneath to the extent that we could and we also applied a treatment to the wood. Luckily my home is of plywood and not particle board. The next step is to refabricate the beam between the two doors as it has the weatherstripping grooves and is a special size. I have to thresholds that are 3 feet each but would welcome a threshold that 66 inches wide. (odd width door) Any suggestions where I can find a 66 inch threshold? Also if I wanted both doors to open and shut suggestions as to where to find French door hardware. (both doors have hinges). Thanks!