Graham, I can't tell from your profile if you have working/flying connections (other than as SLF) so I apologise in advance if I'm stating the obvious to you. The reason for keeping the gear down on the short return flight to Finningley was because it was known to be down and locked. Had the gear been retracted it might have refused to lock into position again with a possible partial gear up landing - not a good idea anywhere and certainly not at what is now a single runway civil airport likely to be full of holidaymakers who would probably be incensed at any resulting delay. Better to use a bit more fuel keeping it down and land safely.