Dunno what to suggest Worty. Keep, fix, sell . . . ??? Dilemmas with sharp horns on all fronts, and questions of 'morality' too if selling with known faults that could be expensive and do affect value.
Think I"d keep for now, on SORN or whatever you guys have, and ponder a lot longer before letting go of something you know you like a lot really . . . More expensive to buy another one if you missed it too much, and if the K got boring. But heck, only one person can decide!
I only have one 22 yr old semi-modern and it does fewer miles than my oldies even though it needs less doing to keep going, because I prefer riding the others.
It's a tough one, no easy answer . .