CAP 509 is a thing of the past, it has been replaced by the JAA Integrated ACPL/IR/ATPL Courses.. .Performance A, B and C is covered in the JAA Performance examinations and again on a Type Rating Course where you are tested on the performance characteristics of the actual aeroplane you are going to fly rather than a mythical one in a stand alone Performance exam.
Remember, recruitment adverts are written by administrators who may be a few years behind the drag curve.