Recovered enough to add my bit:
Huge thanks to all concerned, so many people. Especially grateful to LWAB and HK and co at their Espley Palace of Kindness!
Fantastic event. Time from "Never ever ever ever EVER again" to deciding to enter next year and do it properly: only about 40 hours.
My story: Preparation quite good until last couple of months, when most of it was prevented. So 6.25 for the first 100 miles was too fast(!). But another 100 in 8 more hours was better than feared... things may be ok. Then gradually stricken by something new to me, "leaning over sideways while feeling upright", and a new pain in the back. Stopping every couple of miles to stretch it out, and not riding very straight. Reached the finishing circuit and called it a day (got as far as the second TK, to be sure of passing the 277m VTTA standard for 70yo ... grateful for the decrease since last year!)
Main message: as above. Just huge thanks.