I had a look and have located it....thanks for that. Other than the unit and all that goes with it covered in dust/dirt it looks like the factory original and no additional adjustments have been done. the only thing I did noticed was the adjustment screw where the arm pivots is not sitting on the arm. there is a bit of movement before the arm actually touches the adjustment screw (at least a couple of mm) The spring is tensioning the arm, meaning the surface of the arm and the head of the adjustment screw does not touch.