Incidentally, if you've already flown a PA28R on a non-NPPL, there is no requirement for any further signatures, tests or checks to fly it on an NPPL (SSEA).
Am I not correct in thinking that difference training is only valid for 12 months if the appropriate type is not flown in that period? So unless you have flown the VP prop or retractable within a year you require further difference training. Or is this just for the PPL, not the NPPL?