I have done replacement on one of these before and it was a bit of nightmare!! The problem was freeing the twin joint in the centre section... It was easy enough to undo the clamps between the front section and the centre section; the difficult bit was undoing the joint where the male part of the front section enters the female pipe of the centre section. I spent about an hour chiselling away the solder ring... is there any way of separating this soldered joint easily? Thanks for your help and advice!