Tom,
Not quite sure what M4's PM consisted of but by my understanding is that you can go onto PES at your IPP. The "letter" was not that clear as it did not specify (for your case) whether
your IPP is now five years hence from being commissioned or your old enlisted IPP or indeed (if applicable) the AFPS 05 IPP......I think it might be wise to speak to Glasgow to get the straight and skinny....Maybe not!!