Sorted with the help of Martin, someone in the dim and distant past fell off my bike (before I acquired it), and one of the bits broken was the rear foot rest, exhaust hanger. In actual fact the right one is nearer, which looks better, both will now be dealt with to look the same, i.e. nearer to the rear end.Dave E.
Its done, and now they both look the same, but the left one has a half inch (1.27 mm) spacer between footrest hanger and exhaust can holder to get it the same distance as the right one. Anyone else noticed this problem? the cans are micron carbon race cans.