Nano Banana 2.1 has reimagined the scene for me based on my instruction, although I placed us, from memory, on Waterloo Bridge, but Nano Banana wanted us on Westminster Bridge
Tuesday 31 December 1985 – Had lazy day taping and lounging around – met Petra in afternoon – > John’s -> Poons -> bridge
“John’s” in those days was the flat in Bow that he shared with Mandy, Rachel and I think one or two others.
I don’t list the people who joined us for that meal in Poons and for the celebrations on the bridge afterwards, but it is just possible that either John or Petra will remember.
I’m pretty sure that John’s number one choice of Chinese in those days would have been Joy King Lau. I am guessing that Joy King Lau was full and/or had a longer waiting time than Poons, which I remembered (correctly) was immediately next door in Leicester Street.
Here is a link to my Joy King Lau/Poons proximity question.
My profound love of The Original Poons restaurant in Lisle Street came a little later – other Ogblog pieces might oblige with details of that ultra low key but very high grade Cantonese food place.
As for the bridge in question, my vague memory suggests it was Waterloo Bridge, not Westminster Bridge. I took up this matter with Nano Banana, which responded with the following image, which strikes me as a scene with a view of the Palace Of Westminster that suggests it is roughly where Waterloo Bridge might be:

I’m sure we were all better looking than the youngsters depicted, but maybe we weren’t.
Anyway, here is what I said about the hours following the tolling of the bell:
Wednesday 1 January 1986 – Wandered round the south bankside – took cab – Petra + I hitched back to Bow – bedded down at John’s – hung around at John’s a while in afternoon. Went & had something to eat in Covent Garden – saw Petra off – went home & had lazy evening + early night.
I can’t quite reconcile “took cab” and “Petra & I hitched back to Bow”. Something’s missing in that statement. Perhaps we took a cab to one place, where we dropped some people off, then we hitched the rest of the way.
JOHN! Can you disambiguate this memory?