it's been two evenings of slog to get to this..also decided to fix the exhaust that's always given issues blowing since the stainless went on. One of the studs was threaded halfway up which meant you couldn't get a decent gasket in (the pipe ends aren't the best match by the exhaust makers). Tried removing the stud which of course snapped so drilled it out and made a new one from threaded stainless bar works beautifully, have now got a good fat metal Mercedes gasket in which is perfect for the job...no more blowing and fuming us out (I hope!).
...im off sailing for a week in loch Lomond so if she didn't get away my life wouldn't be worth living. Got lucky and the campsite had a pod thing available, Wood burner un'all she's well happy the camper wasn't ready