thanks Jake, haven't checked yet but had been meaning to lift the carpet, which isn't wet, AFAIK. The car is / has been for a long time stored in a garage most of the time, but is inevitably and occasionally used in the wet. I have sprayed wax inside the sections where the 2 bungs are in the photo and have left one of the bungs out, not sure why they're there TBH, as it must prevent this part from draining if water gets in there, from whatever route. What is the repair process btw, I presume cut out any rot and let in new piece and weld, but are repair panels available or (assuming they're not) one has to custom fabricate a new section from the appropriate gauge steel sheet ?
Im hoping that, once I get the all clear on this / bodywork in general and know there is nothing terminal, I'd like to attend to some of the other jobs I'd like to tackle but have been putting off in case I'm throwing good money after bad, E.g. (sorry going off topic now) engine is ok but showing its miles and needs "fettling", so does anyone know any UK specialists where I can get this done ? I'm a newbie on here, will do a search or post a new thread elsewhere. All I know is that the B18C4 is (I believe) a much sought after power plant, so there ought to be lots of parts available for it to support a rebuild etc. Again, I guess it may not be worth spending loads on such an old car, but I'd just like to get it back to how I remember it all those years ago when I first got it. Although a bit more torque would be nice of course !