So, I discovered several holes in my floorpan today and set about investigating. After some wire brushing, it seems that the interior sills are also rotten in the front foot wells. The driver's side is much worse. After some more wire brushing, I've discovered a previous "repair" where that the floorpan has been cut in a straight line about 3/4 cm back from where it's supposed to flange with the inner and outer sills. The gap has been filled with goo/seam sealer. This is all the way down the car on both sides. Monstrous pita. The flanges on the inner and outer sills are in a horrid state, meaning that they're probably not weldable and will need rebuilding. How egregious a bodge is this, how common is it for garages to do this kind of thing? At the minute, I'm thinking of letting go, but I've got a welder, plenty of metal and plenty of time, so I'm leaning btowards trying to save it.