First, it would be no where near crazy as OTL, because none of the beligerents had the same ability to pay as the Brits. Mean while, a large bunch of Liberals in the government would protest against lending/selling on credit too much. Next, the UK imported most of their oil from the US. Getting oil without paying hard currency would be quite attractive.
The neutral markets also include their home markets. British producers can capture most of these gaps permanently, as German optics, dye, pharma...industries would be geared to war. Besides, keeping traditional markets from countries like Japan would be desirable. And they might even demand Germany to sell some patents, especially chemical, as payments for goods.
And Keynes would eventually have bigger influence in the policies as Liberals still hold the government. The Asquith Social Liberals (no longer Classic Liberal) had begun to move away from the laissez faire approach even before the war, so the government would be even more interventionist than OTL during interwar period.