I still spoke £Sd for some time after decimalisation.......the one thing that sticks in my head is that a Mars bar used to cost 7d and post decimalisation it was 7p = it effectively doubled in price

. And it took a very long time for me reconcile that 15shillings (a lot of money!) was then 75p.,.......it just did not seem or feel like 'real money' for ages
PS as for the 3 day week, I started in the NHS in sept 73 and we worked every day during the Jan to Mar 74 crisis........though the power to hospitals was supposed to be protected, we saw the site generators firing up every so often.
However, where we lived saw us using candles and torches..... the only place on the estate with lights on was the district heating plant, as they produced electricity as part of the plant running.