Thanks crab and Biggus, what you say falls in line with my thinking. I have 3 pension calculator examples, the third of which is leaving next year, just to gauge it.
PVR'ing in the 54th year does indeed appear to be a more financially prudent move (indeed a friend of mine has just retired somewhat early for that very reason). I don't intend to cease working for a living at 55 so the tax-free bonus of the 2nd lump sum does appear inviting.
Many thanks all.