There is no such thing as a PPL/IR.
The route to an IR is to pass the IR written examinations following a course of theoretical training and complete an approved IR flying course, 50 hours for S/E and 55 hours for M/E. If you have 600 hours you can still follow the old UK exemption route so long as you complete it by 30 June 2002.
The big problem is that nobody is offering a theoretical knowledge course for the IR. The last set of National PPL/IR exams is being held in November, the flying is as quoted above.