I feel the approach of simply taking something that worked a bit in one circumstance and applying it in others is simplistic and flawed as an approach. It's a little like the passengers in a car saying we turned Left one time and avoided hitting a tree and so turning left is the way to avoid things. The economy of the UK and our contemporaries in Europe were all on a war footing. We'd suffered devastating losses in human lives, under-invested across the board and had far greater national debt than today (in % of GDP which is the right way to consider it). Liberalisation and obtaining equity for us to bounce back was the right thing to do. We had a baby boom (a natural response to the losses of war) and a great determination to recover. We capitalised on that. And of course contemporaries that doubled down on war time austerity strangled that response in their own economies.
But we haven't just come out of a World War. Our current economic crisis is the result of a over-extending our liability followed by a major US-led market collapse. Which the USA paid their way out of by taking on even more debt.
We had good fundamentals after WWII, including a lack of foreign competition. What we were starved of was capital to make good on opportunities. Today, our problems haven't resulted from war against existential threats, from massive die-offs from influenza or shortage of opportunity. They've resulted from gross mismanagement of the country by successive governments and academia. I'm not sure these problems will be solved by throwing money at them. I'd be willing to try if the money wasn't being borrowed at great expense, but it is. Our population was rising with a surge of new births after WWII. Today it is kept up only by immigration and our population is aging. There are endless differences I could hone in on that are fundamental differences between then and now.
Someone wanting to start a factory or a shop after WWII - a loan makes sense as an investment in our country. Borrowing money to keep paying unemployment benefit or subsidise employers at the tax payers' expense, I'm not so sure about.
Saying "borrowing lots of money worked then so it will work in our very different circumstances today" is dangerous. It's simplistic and faith in it as a principle is misguided. Eighty years ago, we saw a tree in the road and we turned left and avoided it. Today, we see smoke coming from the bonnet of the car and people start yelling "Turn Left, it worked before".
There are no universal solutions in Macro-economics.