Sorry, chaps, I didn't make it (as you may have noticed). The puncture didn't cause a serious delay -- it was just a leaking valve seat -- but the M.25 was appalling. The queue back from the J6 exit was about three miles, so I decided to chance my arm and carry on to J7. There I sat, crawling forward at a fractional mile per hour, for about an hour and a half. When I finally reached J7, I had two choices (North or South); North was stationary, South was flowing freely. But by the time I reached the Gatwick exit the rain was already falling, and I decided enough was enough. I carried on to the next exit, then turned off to East Grinstead, and made my way home via our former window cleaner's home in Tunbridge Wells, who likes curry and who I thought might appreciate some of the egg Madras (I was right : he did appreciate it). Thence home, and just got in now, at about 16:30.
I'm truly sorry not to have made it, but I did my best; the traffic jam on the M.25 was just too much.
** Phil.